CTC-177 Guia de Fallas

8/12/2019 CTC-177 Guia de Fallas

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CTC177Circuit Chassis Part Problem SolutionModel

CTC177 R1904 Set had low audio output which would vary with

the volume. Found pins 2 and 4 of u1901 at .65volts dc, due to r1904, and r1906 increasing in

value. Found resistors to both be approx. 2kohm,

should be 150 ohm.

Replaced r1904 and r1906, which restored full

volume.

Audio

CTC177CD L2304 Low volume and distorted sound. Measuring

voltages we found u1001 pin 2 (if vcc) was 5.2

volts.

Replaced l2304 (u1001-2) which measured 360

ohms.

F31671Audio

CTC177 CF1201 Audio noisy. When connecting an audio source to

th

Found 0 volts at U1001 pin 58. Found pins 2 and

3

Audio

CTC177BH2 U1001 Intermittent crackling in the left channel . U1901

had been replaced .Found that pin 60 of u1001

was at .6 dc supposed to be a round 3.81vdc.

Resistance measurement from ground the l

channel was 60 ohms. Lifting the pin didn't

increase the resistance.

Disconnecting the foil on the pad of pin 60 to

r1901 and hardwiring between pin 60 and r1901

resolved the problem.

F276325EAudio

CTC177BB CF1201 Noisy sound, connecting a sound source to the

audio input jack the sound was ok. Found 0 volts

at u1001-58.

Clipped leads of cf1201, pins 2 & 3 were touching

and grounding u1001-58.

F27150SEAudio



Circuit Chassis Part Problem SolutionModel

CTC177AC CF1201 Noise in audio on cable channels with graphics,

video had audio beat on the same channels. He had

repaired grounds for a vertical problem. Checked

the tuner, it checked normal. After a lot of

clarification of the symptoms I told him to

replace cf1201 the

Removing cf1201 & reinstalling properly cleared

up sound & pic.

F25190SEAudio

CTC177 CF1201 Audio noisy on cable channels with graphics. Video Found CF1201 pin 3 had a bad solder connection.

Re

Audio

CTC177BB ground Slight buzz in audio when graphics or osd is being

displayed. The buzz was also present in the mute

condition.

Resoldering the recommended ground connections

cured the problem.

F27150SEAudio

CTC177 C1953 Audio missing Found C1953 was open. Replacing C1953 repaired

the

Audio

CTC177 OPEN TRA Audio missing U1701 had no signal input at pin 5. Voltage at pinAudio

CTC177 U1901, R1 Audio missing The audio output, U1901, was blown. The

replacemen

Audio




CTC177 TRACE Audio int and Audio noisy on the left channel only Found a broken printed trace going to JW413.

The t

Audio

CTC177 U1001 Audio crackle in the left channel only. Replacing Pin 60 of U1001 measured 0.6VDC, it should be

arou

Audio

CTC177AF2 Trace No audio, u1701 had no signal input at pin 5.

Voltage at the pin was at 0 volts. Lifted the pin

and voltage returned to the pin. Traced signal

from u1001 pin 3 to c1703. Had signal to one side but n ot th e ot her. Meas ured res istance on th e

trace to ground

Jumped trace from c1703 to pin 5 of u170125GT520Audio

CTC177 C1201 Audio distorted intermittently. U1001 pin 57 was at 4.7V instead of 5.9V. C1201

of

Audio

CTC177 JW107 Problem with interface between MCR029 and

external

Remove jw107 from board restored operation of

mcr

Audio

CTC177 JW431 Set had intermitten audio. The audio mute transist Cleaned up the board between the two jumbers fix tCHASSIS:Audio




CTC177 C4124 Tic tic. The set makes a ticking noise after the p Pin 3 of IHVT was cycling between 100V and

125V. W

B+ Regulator

CTC177 R4105 The set makes a Buzzing sound in the off mode. The regulated B+ was high. The set operated

normal

B+ Regulator

CTC177 R4136, C41 Arcing C4107 vents and the regulated B+ was 400VDC.

C4107

B+ Regulator

CTC177 C4007 Standby voltages high. The 140 volt measured 180 volts. The raw B+ had

no

B+ Regulator

CTC177 IR WINDO Remote operates only at very close ranges. Removing the IR window allowed the remote to

opera

Cabinet

CTC177 R2806 No chroma. The waveform on pin 48 of ic1001

was close to 1 v peak to peak for the luminance

signal but on pin 49 there was not any waveform

for the chroma. There was chroma on both sides

of c2805 but it was only on one side of r2806 on

the foil. Resolderi

Resolder r2806Chroma




ctc177 c2806 No color. Applying 4 volts to pin 47 of u1001 to

defeat the color killer brings back good color. Had

replaced u1001 and y2801. The dc voltage on pin

47 was slightly low, 3.3 volts. Found that lifting

c2806 (off of pin47) allowed the dc to rise to

3.75 vo

Replaced leaky c2806.25GT522Chroma

CTC177 N\A No color on channel 3 only. Reverse instructions on sps 4313 packed with

211962. Change r2805 to a 750 ohm (215200) at

coordinates 16b & c2801 to 1uf (189991) at

12ee. Replace r2806 at 16b with a chip jumper

(205408).

G27683HPChroma

CTC177AF3 R2801 Set had no color and in troubleshooting found pin

47 of u1001 to be 3.3 volts due to one side of

r2801 not soldered.

Soldered r2801Chroma

CTC177 C2801 Intermittent color. pin 47, u1001 measured 2.2v.

it should have measured 3.6v. found a leaky

capacitor (c2801) off of pin 47, u1001.

Replacement of c2801.Chroma

CTC177BE U1001 No color, no station audio (noise only). Would

direct access channels, but tuning was slow.

Autoprogram wouldn't capture anything due to

slow tuning. Checking around y2801, we found

that u1001-15 measured 9 ohms to ground.

Replacement of u1001 restored no

Replace u1001.F27631SFChroma

CTC177 R2806 Chroma missing. The waveform on pin 48 of IC1001 was close to

1Vp-

Chroma




CTC177 R2801 Color missing. Pin 47 of U1001 measured 3.3V. There was a bad

sol

Chroma

CTC177 C2806 Color missing Applying 4 volts to pin 47 of U1001 to defeat

the

Chroma

CTC177 C2805 Color missing. Video was normal but was in black a There was video out at pin 51 of IC1001, but no

co

Chroma

CTC177 C2805 No color video okay in black and white. Had

video out 51 but no color back in pin 49 of

ic1001. Ic1001 and the 3.58 crystal had both been

replaced before the servicer call tech. line. Found

color on one side of c2805 but none on other side.

Resolder cap. and color was restored. C2805 is the

pat h fo r co lor to p in 4 9.

Chroma

CTC177 R5014/16 Red picture. Low drive from q5002 and q5003.

Servi

Replacement of resistors R5014/16 restored

pictu re

High Voltage

CTC177 C7410 High Voltage @ 10KV; 26V, 12V, -12V Run

sources OK

Replaced c4710.High Voltage




CTC177 R4904 Dead set There was 2.5V on pin 26 of U1001. U1001 had

been

High Voltage

CTC177 R4119 Vertical int The 7.6V run source was varying at pin 32 of

U1001

High Voltage

CTC177 TRACE 14 Video missing/OSD missing. Audio was normal. Normal video was present at U1001-44. checked

U100

High Voltage

CTC177 T4301 Dead. hot had shorted and f4001 had opened

.found connections at primary of the horizontal

driver transformer t4301 bad.

Resolder connections at the horizontal driver

transformer t4301.

Horizontal

CTC177 C4403 Insufficient horizontal sweep.horizontal near

collapse. Tracing waveforms at the yoke return

capacitor the signal dropped off dramatically on

one side of the capacitor.

Replaced open c4403.Horizontal

CTC177 CR4402 Pincushion error evident. Servicer found shorted

q4851 pin out put transistor. Upon replacement

the new part promptly went up in a puff of

smoke. Pulling the collector loose on the pin

output, the dc level on the foil was at 39vdc with

horizontal ac also

This applied reg b+ to the pin circuit thereby toast

ng q4851. Replacement of the above components

restored normal operation

Horizontal




ctc177 short Dead data and clock line from u3101 were not

prese nt, wh ich i s cor rect and t hey would s tart up

when the power button is hit. There is no dc

voltage on pin 24 of u1001 the trace from r4311

to jc404 was reading 0 ohms to grnd.. Found trace

under r4308 was

Removed short.Horizontal

CTC177 R2709 Bright screen no video pin 31 of u1001 was 7.4

volts instead of 6.36.

Found resistor r2709 (27k) was open. Resistor is

off pin 4 of flyback.

25GT506Horizontal

ctc177 r4904 Dead. Found 2.5v on pin 26 of u1001. U1001

had been replaced. Found r4904 open. Pin 26

pulled up fro m insid e u1001 .

Replaced r4904 and set worked.f25651Horizontal

CTC177 C4403 Dead set with c4105 failure. replacement of

c4105, chassis will run for a very short time with

c4105 failing again. replacement of c4403 (yoke

return cap) resolved the problem.

Replacement of c4403.Horizontal

CTC177 CR4303 Found the horizontal pulse at q4301 to be 5.7vpp

and -2.3vdc at the base, and .4vpp and 145vdc at

the collector. Cr 4303 checked open.

Replaced cr4303, restored operation.Horizontal

CTC177AA3 TRACE Dead set. Pin 24 of u1001 was at 1.5 volts in

standby it should of been 6 volts. There was

leakage in the trace at the two jumpers jc404 and

jw31 7 of f pi n 24 of u 1001 .

The two jumpers were removed and a wire jumper

was placed between resistors r4311 and r4310.

Horizontal




CTC177AG leakage Turning tv on, it came up than down. Grounding

pin 26 o f u1 001 tv s taye d on with cor rec t hig h

voltage. Checking voltage on q4901-b found 7.5

volts. Also, found 700 ohms across xrp test points.

Tech removed printed wire between r4902 & xrp-

1 and replaced with a jumper. Leakage in circuit

board.

F25651Horizontal

ctc177 trace Dead. U3101 pins 15 and 16 ok. U1001 pin 26

(xray shut protect) at 2.6v.

Found and repaired an open trace between pin 26

and r4904. Set then worked normal.

25gt506Horizontal

CTC177 CR4403 Pincushion problem.repeat failure of q4851 in the

pincushi on circ uit. the v oltage a t the coll ecto r of

q4851 was down to about 12 volts .it should be

about 17 volts.cr4403 was checked out ofcircuit(it checked good).the diode was breaking

down under load.

Replacement of cr4403 as well as the damaged

q4851.

F27631SFHorizontal

CTC177 T4301 Dead set. T4301 had an open primary winding.

Set w

Replacement of T4301 repaired the setCHASSIS:Horizontal

CTC177 connection Picture pulled in 1 to 1.5 inches on both sides.

Found pin 2 of l4853 not soldered. This

connection was on the coil not the board.

Resoldered l4853.G27683Horizontal

ctc177 c4407 Picture is too tall and bowed out at the top. The

sides are bowed in.. The collector voltage on

q4851 is at 19vdc.. The vertical height can be

controlled by the service menu...

Replaced def c4407.. Cap checked good out of cktHorizontal




CTC177 C4303 Narrow pix. Horizontal waveform at collector

showe

Remove solder splash c4303 (emitter q4302).Horizontal

ctc177 t4401 Dead. Set was intermitant initially. 140v was at

148. Checking voltages we found a poor solder

connection on pin 1 of the fly.

Repair of solder connection fixed set.f27631sf Horizontal

CTC177 trace No video or osd- audio normal had changed

u1001. Found normal video at u1001-44. Checked

u1001-25 for 8vpp horiz. Pulse and found no

pulse wi th 6vdc (should be 2.1vd c). Foun d anormal 25vpp pulse at t4401-8, but not a t r4303.

The trace between t4401-8 an

Repair trace27GT613Horizontal

CTC177 CR4402 Hot failure.found cr4402 leaky. have seen a few

of these diodes failing.

Replaced q4401. cr4402.Horizontal

CTC177AM2 Originally the set had a blown horizontal output

transistor. After replacement the sides pulled in

and pincushion correction was not correct. The

servicer had replaced c4402, c4406 and the yoke

return caps without any improvement. This set

has a 27 inch t

When the servicer reinstalled the chassis back into

the original set the width and pincushion problem

disappeared.

Horizontal

ctc177aa3 Q4301 Turn set on would have drive out of u1001-24 to

base of q4 301 no colle ctor wave form and h ad

17v on collector. Tech may have caused this,set

came in for ground problem and the set would not

turn on after he soldered the set.

Replace q4301x25103sgHorizontal




CTC177 C4403.HO Intermittent failure of the hot. found an open

(under load) r4403 and a intermittent c4403. the

set had worked briefly with the first hot

replacement.

Replacement of q4401, r4403, c4403.Horizontal

CTC177 T4301 Dead set. Tracing the horizontal drive signal revealed thereHorizontal

CTC177 C4407 Picture would bloom with channel changes or a

change of screen voltage. Width was also affected.

Replacement of c4407 which is located across the

pincu shion dampe r re solved the probl em.

Horizontal

CTC177AR2 R2709 Intermittent vertical black bar in center of

pictu re. Fo und r2709 overheat ed.

Replaced overheated r2709 (ihvt pin 4).F25215WHorizontal

CTC177BE C4313 No video or osd, replaced u1001, 3201 and 3101.

Pin 25 of u1001 had 4.3 volts with a waveform of

only 2.1 volts peak to peak.The servicer noticed

c4313 in parallel. Lifting the cap returned video

and osd. Checking the service lit and c4313 is not

shown. T

Replace c4313.F27630Horizontal

CTC177AA R4201 Intermittent xrp shutdown . By grounding pin 26

of u1001 the set would operate. The base voltage

on q4901 would vary lower causing the xrp to

trip. The base of q4901 read 13k to ground.

Removing r4201 off from it's pad and cutting

along the foils with a k

Removing r4201, cleaning the traces underneath

this resistor and reinstalling this component took

care of the problem.

25GT506Horizontal




ctc177bg q4851 Picture is too wide. Horizontal freq. Was set ok.

Read a short across cr4403 in circuit.

Found q4851 shorted c-eg27341wk Horizontal

ctc177 c4402 Cycles when turned on. Found by substitution

c4402 bad.

C4402.x25101Horizontal

CTC177 PCB Dead set.chassis tries to power up.found the 140

volt supply missing at the collectors of both the

horiz. Driver and output.found an open trace at

pin 2 o f t he ihv t.

Repaired open trace.Horizontal

CTC177 T4301 No high voltage had drive to horz driver transistor Horz driver transformer t4301 had a broken wire

at terminal # 3 was able to repair.

27GT613Horizontal

CTC177 C4706 Dead set servicer had replaced cr4704 and r4702

the run voltage came up to 4 vdc. Tried another

diode but the voltage remained low. Re- moved

one end of c4706 and restored the 12vdc.

Replaced c470625GT542Horizontal

ctc177 trace Dead set. Clock and data on u3201 pins 5 and 6

are ok. Found drive for horizontal coming out of

u1001 pin 24. Found open trace between l4401

and pin 6 of t4301.

Jumped trace with wire fixed set.Horizontal




CTC177AF2 C4307 Set had zig zag lines in the top 4" of the picture.

Checking waveforms on the set showed what was

described as a ringing in video and horiz drives.

Subbing in a horiz drive at pin 24 of u1001 clear ed

up the picture. Checked voltage at pin 23 and it at

.5

Replace c4307.F26251ETHorizontal

CTC177BH2 T4301 Dead. Tracing horizontal drive signal we found

only 18v p-p on the collector of q4301.

Replaced t4301 which checked 17 ohms across

the primary (should be 37.8 ohms).

27GT613Horizontal

CTC177AK R4302 No video or osd no sandcastle at u1001-27, at pin

25 the fb pulse was 7vpp but was clipped. Dc was

2.7vdc. Checking r4302 for resistance, it checked

open (should be 22k). Substitution of a 22kresistor across r4302 restored video and osd.

Replacement of r430225GC710Horizontal

CTC177BF CR4302 Set would get a black bar on right side of pix from

top to bottom. Over a period of 3-5 min more

bars would ap pear a nd they would g et thicker.

Slowly the pix would be blacked out from the right

side to the left. Sandcastle pulse at pin 27 of

u1001 was wr

Replace leaky cr4302 clamp diode27GT617Horizontal

ctc177 c4403 No horizontal sweep. High voltage present.

Servicer found and replaced defective c4403 and

cr4401.

Replaced c4403 and cr4401. j253 30blHorizontal

ctc177 adjustment Flagging at top on tuner and vcr. Readjusting the

horizontal oscillator corrected the problem.

Servcier said the adjustment was a couple of

numbers off.

Reset horizontal oscillator.Horizontal




CTC177 C4307 Flagging at the top of pix with tv video and aux

video. All voltages off pins 20,23 and 25 of

u1001 checked ok.

Replacing c4307 (off pin 23 of u1001) cured the

prob lem.

Horizontal

CTC177 CR4403 Pincushion problem. Repeat failure of Q4851 in the pincushion circuit.Horizontal

CTC177 TRACE Dead set Clock and data on U3201 pins 5 and 6 were

normal.

Horizontal

CTC177 R2709 Pix narrow Voltage checks around U1001 indicated a problem

at

Horizontal

CTC177 C4402 Cycles on/off when turned on. C4402 was bad. Replacing C4402 repaired the set.Horizontal

CTC177 T4301 Hi voltage missing. The set had drive to the horiz The horizontal driver transformer (T4301) had a

br

Horizontal




CTC177 C4706 Dead set The run voltage came up to 4VDC. Removing one

end

Horizontal

CTC177 CR4115 Dead set All standby voltages were normal. The

microprocess

Horizontal

CTC177 R2709 Bright screen/Video missing Pin 31 of U1001 was at 7.4 volts instead of 6.36 vHorizontal

CTC177 CR4402,C4 Dead set CR4402 was shorted. C4701 and C4505 on the 26

volt

Horizontal

CTC177 C4502 Dead set HOT leads were severed on the PCB. After

replaceme

Horizontal

CTC177 HEAT SYN With the antenna connected, the set would Pulse

on

The heat sync that the horizontal output was

mouun

Horizontal




CTC177 CR4402,U4 Dead set. When plugging the set in, a chirping sou A short was detected across the horizontal outputHorizontal

CTC177 T4401 Dead set. Initially, the set operated only intermi The 140V supply measured 148V. Checking

voltages r

Horizontal

CTC177 C4311 Dead set U3101 voltages were normal. Had no drive from

U100

Horizontal

CTC177 CBA Dead set U3101 pins 15 and 16 were normal. U1001 pin

26 (Xr

Horizontal

CTC177 CIRCUIT T No Pincushion correction. Pix narrow with sides

bo

Checking waveforms and voltages in the

pincu shion

Horizontal

CTC177 L4853 Pix compressed. The picture was pulled in 1 to 1.5 Pin 2 of L4853 was not soldered. This connection

w

Horizontal




CTC177 CBA Dead set U3101 had normal voltages. Pin 15 had data when

th

Horizontal

CTC177 Q4302 Shutdown int after resoldering ground connections Q4302 base connection did not have any solder

on i

Horizontal

CTC177 Q4851 Pix narrow The collector voltage was low on Q4851. Q4851

was

Horizontal

CTC177 T4401 No Vertical/Audio missing. The voltage at diode CR4704 cathode was 0VDC.

Chec

Horizontal

CTC177 T4401 Dead set. The power supply made a singing noise. The collector of the horizontal output transistorHorizontal

CTC177 CR4402 Dead set int Intermittently Q4851 would overheat and open.

The

Horizontal




CTC177 CR4402, Q Pincushion error. The Q4851 pin output transistor was shorted.

Upon

Horizontal

CTC177 Q4401 No startup/Dead set. If the chassis was positioned Resoldering the tabs at the system control shieldHorizontal

CTC177 Q4401 Dead set The heat sink where the horizontal output was

moun

Horizontal

CTC177 CR4402 Dead set When the set was plugged in, parts on the 26V lineHorizontal

ctc177bh2 r4854 Pix on left side bowed. Cannot adjust out. U4851

4.5v on pin 2 and 3. R4854 is a 27k resistor

instead of 41.2k

Replaced with 41.2k resistor.f27632seHorizontal

CTC177 C4405 Dead set. The set had a repeat failure of CR4401. IsolatingHorizontal




CTC177 R4854 Pix bowed in on left side. Could not be adjusted. Checking U4851 4.5V on pin 2 and 3 showed

R4854 re

Horizontal

CTC177 R2709 There was an intermittent vertical black Bar in pi R2709 (IHVT pin 4) had overheated. Replacing

R2709

Horizontal

CTC177 TRACE Dead set The foil at pin 2 of the flyback transformer was oHorizontal

CTC177 E4403 Dead set. Pin 24 measured zero volts, it had 990 ohms to

gro

Horizontal

CTC177 CR4403 Pincushion distortion with repeat failure of Q4851 The pin damper diode CR4403 had physically

deterio

Horizontal

CTC177 CR4303 Dead set. The horizontal pulse at Q4301 was 5.7Vp-p and -

2.3

Horizontal




CTC177 C4307 Flagging at the top of the picture with TV video a All voltages off pins 20, 23 and 25 of U1001 wereHorizontal

Ctc177 C4311 Dead set, u3101 voltages normal, no drive from

u1001 pin24 voltage on base of q4302 near 0.0.

R4301 had 7.6 volts on one side, 0.0 on the

other. Lifted c4311 and voltage and drive returned.

Replace c4311Horizontal

CTC177 E802 Video missing. There was no pulse at pin 25 of U1001. Pin 25 of

U

Horizontal

CTC177 c4401 TV would not turn on instantly. Followed

horizonta

Replacement of c4401 and set turned on and off

oka

Horizontal

CTC177 C4307 Lines in pix. The set had zig zag lines in the top Checking waveforms showed a ringing in video

and h

Horizontal

CTC177 R4201 Shutdown intermittently. The unit would enter

into

The base voltage on Q4901 would vary lower

causing

Horizontal




CTC177 C4313 Video missing/OSD missing. U1001, U3201 and

U3101

Pin 25 of U1001 had 4.3V with a waveform of

only 2

Horizontal

CTC177 Q7404 VHF channels were Snowy. Found Q7404 was shorted with 11 volts on the

colle

Horizontal

CTC177 CR4302 Intermittent Jailbars. CR4302 checked good but was defective.

Replacing C

Horizontal

CTC177 CR4302 Video missing/OSD missing/Screen black. U1001 pin 25 was at 4.3VDC and pin 27 was at

2.8VD

Horizontal

CTC177 R4854 Pix bowed in on left side. U4851 measured 4.5V on pins 2 and 3. Found

resisto

Horizontal

CTC177 JUMPER Turning the TV on, the set comes on and then

Shutd

Grounding pin 26 of U1001 caused the TV to stay

on

Horizontal




CTC177 C4403 Horiz sweep was insufficient. The horizontal was n Tracing waveforms at the yoke return capacitor

rev

Horizontal

CTC177 CR4302 Black bars would appear on the right side of the p Sandcastle pulse at pin 27 of U1001 was incorrect.Horizontal

CTC177 C4403, CR Horizontal sweep missing. High voltage was

pre sen t

Found C4403 and CR4401 were defective.

Replacing C

Horizontal

CTC177 Q4851 Pix wide Horizontal frequency checked normal. Detected a

sh

Horizontal

CTC177 TRACE Dead set There is no DC voltage on pin 24 of U1001. The

tra

Horizontal

CTC177 PCB Dead set. Chassis tries to power up. Found the 140 volt supply missing at the collector Horizontal




CTC177 T4301 Dead set HOT had shorted and F4001 had opened. Found

connec

Horizontal

CTC177 C4407 Pix tall and Pix bowed at the top and sides are bo The collector voltage on Q4851 was at 19VDC.

The v

Horizontal

CTC177 R4302 Video missing/OSD missing Had no sandcastle at U1001 pin 27. At pin 25 the

F

Horizontal

CTC177 R4301 Dead set Found voltage and output missing on pin 24 of

U100

Horizontal

CTC177 R4854 No Pincushion correction. Varying parameters P03 and P04 had no effect on

th

Horizontal

CTC177 CR4402 Dead set Found cr4402,cr4403 and q4851 shorted.G27343HPHorizontal




CTC177 T4401 No vertical or sound. Checking voltage at diode

cr4704 cathode we found 0vdc. Checking between

pins 5 an d 9 o n t44 01 we fo und a n op en

Replace t4401F31631SEHorizontal

CTC177 T4401 Dead unit. Power supply making a singing noise.

Checking the collector of the horz output

transistor to ground read shorted. Isolating the

various other components off t4401 pins 1, 2,

and 3 we still had a short. Flyback (t4401) shorted

pin 3 to cor e

Replace t4401G25341WK Horizontal

ctc177bh2 r4301 Dead. No volts or output on pin 24 of u1001.

Found r4301 present but not soldered in.

Soldered r4301.27gt613Horizontal

CTC177BH2 CR4302 Intermittent jailbars. Cr4302 checked ok but when

it was replaced it took care of the problem.

Replaced cr430227GT613Horizontal

CTC177 R4303 No picture with strong signal and tearing with

weak signal. Less than 1v p-p at u1001-25.

Replaced open r4303 which supplies flyback pulse

to u1001-25.

F25651Horizontal

ctc177 CR4402 Intermittently q4851 would overheat and open.

Found the cathode lead of cr4402 was long enough

so that when the chassis was slid into the tray it

caught on the tray and broke the circuit trace.

The break would intermittently connect and the

unit would wo

Repaired connection on cr4402 and the board

around q4851.

G27665wk Horizontal




CTC177 Q4851 Slightly narrow pix. Collector voltage low on

q4851

Found q4851 leaky base to emitter.27GT617Horizontal

ctc177 cr4402 Dead set. Replaced shorted u4101 and it blew

again immediately. Svcr found cr4402, damper

diode, shorted. After replacement of cr4402, and

u4101 again, it worked.

Replaced cr4402 and u4101 again.F27150seHorizontal

CTC177 Q4401 No-start. If the chassis was positioned vertically

as for servicing the bottom side, the set would

start and play normally. Resoldering the tabs at

the system control shield did not help. When the

horizontal output transistor leads were resoldered,

the c

Extending the lead through the chassis and

soldering restored normal operation.

G27681CK Horizontal

CTC177 Q4401 No pix no high voltage. Traced horz signal out of

the collector of the horz driver transistor.

Found base lead of q4401 (horz output) broken.G27687WAHorizontal

CTC177 CR4402 When set plugged in parts on 26v line blow up.

C4701, c4705, c4506, c4505, q4851, c4853 all

vented or shorted as soon as set was plugged into

wall. Other parts on the 26v line may also be

damaged. The cause was a shorted damper diode

cr4402 putting 140v

Replace cr4402 and all failed components on the

26v line.

G27343HPHorizontal

CTC177 Cr4402 Dead set. Upon pluging the set in a chirping

sound was heard. Found a short across the

horizontal output which turned out to be cr4402.

Replacing cr4402 brought the set back to life but

it had no vertical deflection. U4501 cured the

vertical problem but

Cr4402 shorted damaging u4501 and q4851.G27665Horizontal




CTC177 CR4402 Dead set cr4402 was shorted also found c4701

and c4505 on the 26 volt supply were shorted.

Replaced cr4402 c4505 and c4701F27150SEHorizontal

CTC177 R2709 Picture is narrow. voltage checks around u1001

indicated a problem at pin 16.the voltage was

higher. traced problem to an open r2709 in the

beam se nse line tha t co nnects to p in 4 of t 4401 .

Replaced r2709.Horizontal

ctc177 trace Dead u3101 had voltages ok. Pin 15 had data

when power pressed. Pin 24 of u1001 had a

waveform. Traced to an open trace between pin 6

of t4301 and l4401.

Repair of trace repaired set.g27665wk Horizontal

ctc177 cr4402 Unit came in with almost everything on the 26v

run line blown. T he servicer replaced c4701,

cr4701, r1908, c1909, and u1901 (audio). When

he plugged the set in it blew all of these out again.

We found a shorted damper diode, cr4402,

allowing reg b+ into

Replaced shorted cr4402.27gt614Horizontal

CTC177 trace Overloaded pix. Agc too high. Co channel

interference and some times snowy pix. Flexing

the chassis the problems clear up. Found trace

from pin 1 of the saw filter ( sf2301 ) to c7605 in

the tuner area cracked.

The foil was cracked just as it ente rs the shielded

area. C7605 is off q7601 collector.

F25251WNIF

CTC177 U1001 Slight distortion in tuner audio, aux audio is clean.

All voltages are normal. Waveform at pin 3 of

u1001 has a slight distortion in it. Replacement of

u1001 fixed problem

Replace u1001F27631SFIF




CTC177AF trace Snowy picture on all channels. Corrected broken trace between u1001-6 and

r2316.

25GT520IF

CTC177 GROUND G Tuning weak in all bands. Hi VHF was worse. All voltages at varactor and switching diodes checIF

CTC177 U1001 Tuner Audio distorted. Aux audio is normal. All voltages checked normal. The waveform at

pin 3

IF

CTC177 Q7601 When changing channels, the picture would lock

in the drift to snow. Monitoring the tuning

voltages at the varactor diodes showed no change

when the channel would drift off. Had a if signal

inputted off pin 1 of u7301 and got the same

results. Traced faul

Replace shorted if amp, q7601.IF

CTC177 CBA Video distorted The AGC was too high. There was co channel

interfe

IF

CTC177 C2307 SOL Tuner inop. All channels are snow. The AGC voltage at pin 12 of U1001 remains at

0V o

IF




ctc177 alignment Rf agc stuck at 8v all the time. Picture is going

into agc overload. Controlling the agc from an

external source we got a good signal through.

Servicer had changed u1001 and u3201. Adjusting

the 4.5mhz trap in the eeprom corrected the a gc

probl em.

Eeprom adjustment.IF

CTC177 C1201 Audio buzz only on some channels. A VCR was connected to the aux-1 inputs. One of

th

IF

CTC177ac Ground Weak tuning all bands all voltages at varactor and

switching diodes checked good. Checking if amp

q7601 found 12vdc on coll. and 0vdc on base and

emitter. Resistance from base to ground measured

less than 1 ohm. Found that tech had bridged the

base circui

Removal of solder bridge at grid 20f restored tuner

operation.

F25190IF

ctc177 c1201 Audio buzz only on some channels. Servicer tried

changing c4129 to a 100uf but the symptom was

the same. He then connected a vcr to the aux-1

inputs, tuned one of the bad stations on the vcr,

and switched between tv and vcr listening to the

same station

Changing this defective c1201 fixed the set.G26685wk IF

CTC177 SF2301 Video int. When video was input to the external ja All the voltages in the tuner checked normal. SubsIF

CTC177 TRACE Pix snowy on all channels. Found a broken trace between U1001 pin 6 and

R2316

IF




CTC177 C2307 Tuner signal missing. DC voltage on U1001 pin 12 measured zero volts

and

IF

CTC177 L2302 Very snowy or no pix sound ok. Servicer found

that moving coil l2302 would make pix come and

go. Replacing coil cured prob. Servicer said he has

seen two of these.

Replaced l2302G31641CK IF

CTC177 EEPROM AGC overload. The AGC was stuck at 8V all of the time. ControlliIF

CTC177 C2307 All channels are just snow. Agc voltage at pin 12

of u1001 remains at 0v on all channels. Checking

pins 13 & 1 4 of u100 1, we foun d le ss th an 1 v on

both. Resis tance from pin 14 to gro und measured

800 ohms.

Found and removed a solder splash from c2307 in

the circuit off u1001 pin 14.

F25190SEIF

CTC177 SF2301 Intermittent video input of video to the external

video jack worked okay. All the voltages in the

tuner checked okay. Subbing IF signal no video.

The saw filter was intermittent.

Replace saw filter F27351IF

CTC177 C2313 No video from the tuner. Unit had a slick raster

not snow but had static for audio. Found 2vdc on

pin1 3 of u100 1. Di scon nect pin 12 and vi deo

came back.

C2313 checked good out of ckt. Replace c2313

and the unit worked fine.

IF




CTC177BH2 C2307 No tuner signal. Dc voltage on u1001-12

measured 0 volts and about 2 volts on pins 13 &

14 of u1001.

Replaced leaky c2307 (near u1001-14).27GT613IF

CTC177 C2313 Video missing from the tuner. There was 2VDC on pin 13 of U1001.

Disconnecting p

IF

CTC177 L2302 The set had a very Snowy pix or Pix missing.

Audio

Moving the coil (L2302) would make the picture

com

IF

CTC177 Q2301 Unit had no voltage at pin 12 of u1001. On

checkin

Q2301 shorted.IF

CTC177 17J STRIP Keyboard func inop Lifting the shunt capacitors, the keyboard would f Keyboard

CTC177 JW427, JW Front panel cntrls. No menus were present when

the

There was a solder bridge from JW427 to JW428.

Rem

Keyboard




CTC177 SW3410 Dead set. The standby supplies were normal. There was no data at U3101-15/16. Checking

U3101 p

Keyboard

CTC177 S3411 Power button inop. The TV would not turn on

with t

Removing a solder splash near the power switch

(S3

Keyboard

CTC177 PCB Functions inop. The set turns on when the volume

u

There was leakage between pins 5 and 6 of

U3101. R

Keyboard

CTC177 C3106 The set Turns on/off intermittently. The voltage on pin 5 of U3101 was fluctuating up

a

Keyboard

ctc177 board Set turns on when vol up button is pressed. When

on channel up and down work but no other

controls will operate. Found leakage between pins

5 and 6 of u3101. Removing components off of

pins 5 and 6 and cl eanin g board remo ved leakage .

Components were put b

Cleaned pcb.Keyboard

CTC177 SW3431 Front panel inop. Measured a short from pin 2 to pin 5 on the frontKeyboard




CTC177 C3103 Volume control inop. The volume down control

on th

The microprocessor had been changed. Pin 7 of

U310

Keyboard

CTC177 C4501, C45 Vertical will pull up from the bottom intermittent Pressing down on C4501 and C4503 will cause the

ve

N/A

CTC177 Y7401 Tuner inop. The band switching was normal. The tuning

voltage

N/A

CTC177 C5002 CRT shorts. G1 voltage remained high when disconnected from

th

N/A

CTC177 C7404 Tuner inop The tuning voltage on the collector of Q7401 was

f

N/A

CTC177 C4506, U4 The neck of the CRT was burned off. Had apparent high current through yoke windings.

F

N/A




CTC177 R7117 Tuner inop/Snow on screen Tuning voltage on Q7401 collector varied with

chan

N/A

CTC177 R7412 VHF low band was missing. High band was normal. The collector of Q4702 was at zero volts in low

VH

N/A

CTC177 C4129 Audio buzz Changing C4129 from 10UF to 100UF (part

number 194

N/A

CTC177 GROUND Audio buzz when graphics or OSD were being

display

Resoldering the recommended ground connections

eli

N/A

ctc177bf c7304 Only snow. Q7401 volts changed to proper

voltage for channels we selected. However the

voltages on u7301 were all wrong. Pin 8 had 3vand the chip was loading it down. Pin 7 had 3v

(the only correct voltage) most of the pins had

0v. Checked resistance to

Cleaned c7304 off of pin 5 of u7301 to repair the

set.

N\A

CTC177 R7117 No tuner signal and snow on screen. Tuning

voltage on q7401 collector varied with channel

change. Found zero volts on q7102-g1.

Replaced open r7117.F25651BL N\A




ctc177 c2708 Intermittent red components of osd. Off of

u1001 pin 40 c2708 was in backwards.

Replacing c2708 and putting in correctly solved

prob lem.

g27687wklOSD

CTC177BE Q2701 No green in menus q2701 (g-osd driver) had

correct waveform at base and emitter, but the

emitter waveform was not reaching the negative

side of c2707, which should have been a direct

connection. The trace between q2701-e and

c2707 checked good up to the f

Soldering q2701-e repaired set.F27631SFOSD

CTC177 R3311 No osd. found fsw signal missing at pin 39,

u1001.there was signal at pin 22, u3101.found an

open r3311 (connected to pin 39 u1001).

Replacement of r3311.OSD

CTC177BG U1001 Channel number and vol. indicator were red,

menus were red blocks with no information

displayed. U1001-40 (red osd input) had a normal

waveform, but the dc level was 2v too high at

7.4v tech replaced u1001, and normal voltage and

osd returned.

Replace u1001.G27341WK OSD

CTC177 CRT Pix green. The set had a faint green box in the pi Traced back from U1001 to the kine drive PCB.

When

Picture Tube

ctc177 yoke Set would squeal when turned on. Horizontal

output, q4401, was shorted when the set came in.

No scan deri ved vol tages. The vol tage would

return and the squealing would stop with the horiz

yoke unplugged. Set also drew 2 amps of current

with the yoke plug

Replaced picture tube, bad yoke.25gt522Picture Tube




CTC177 CRT, Q440 When the set is powered on, it will Squeal followe Components off of the collector and the base circ uPicture Tube

CTC177AF C5002 The raster is bright with retrace. The g1 voltage

was 180 vdc. We removed the socket. The

voltage was still at 180 vdc. We removed r5007.

We still had 180 vdc. At this point we removed

c5002. It measured 14k ohms. The 180 vdc

dropped to about 16 vdc.

Replaced shorted c5002F25251WNPicture Tube

CTC177 CRT When the set is powered on,the set will squeal

followed by a failure of the hot. checking the

various items off of the collector and the base

circuit checked normal.disconnecting the crt

allowed the set to turn on and stay on.the servicer

had a couple se

Replacing the crt.F26251SEPicture Tube

CTC177 CR2901 Pix flickers slightly in the background. Found a bad solder connection on the cathode of

CR

Pix/Pix

ctc177ac R3116 No video. Found pin 22 of u2901 at 0v traced

back to u3 101 p in 12 and found r311 6 mis sing.

Tech induced

Installed r3116Pix/Pix

CTC177 R7306 Cable channels 2 through 48 tune poorly. Tuner. Checking tuning voltages found junction of

CR7302

Pix/Pix




CTC177 R2908 No pip or box for the small picture. Main picture

was ok. Measuring voltages we found the voltage

low on u2901-20.

Replaced open r2908.F25190FEPix/Pix

CTC177 C2918 PIP inop. The set had been hit by lightning and U2 Pins 1, 26, 25, 13, 18, 7 and 9 of U2901 were at zPix/Pix

CTC177AE R2909 No video. Traced video signal to u2901, but had

no output. Checking pins 20-22, we found data

information on 20 and 21 but pin 22 was at .3

volts. U3101 pin 12 was at 4.8 volts. Following

the line up to u2901 we found one side of r2909

unsoldered. Resolde

Resolder r2909G26681CK Pix/Pix

CTC177 R2908 PIP missing, the box for the small picture was mis Found the voltage on U2901 pin 20 was low.

R2908 w

Pix/Pix

CTC177 SOLDER R Pix flickering The flickering resembled a video picture of a TV pPix/Pix

CTC177 TRACE Video missing Video was lost at PIP IC. Pins 11 and 12 of

U2901

Pix/Pix




CTC177 R902 Normal color on big picture, has color sync

prob lem on pi p. While examinin g ci rcui try at

u2901, found r2902 (connecting to pin 24,u2901)

was mounted incorrectly on the board (90 degrees

off) not completing the circuit.

Removing the mispositioned r2902 and installing

a new one fixed the set.

F27671Pix/Pix

CTC177AE C2918 Set hit by lighting, u2901 and u2902 had been

replaced. Found pins 1, 26, 25, 13, 18, 7, and 9 to

be 0 vo lts, whi ch was due to c2918 b eing sh orted

off the 14.318mhz crystal.

Replaced c2918Pix/Pix

CTC177 SOLDER Good main pix video, pip video looks like a double

image. In checking pip micro, u2901 tech noticed

a solder bridge from pin 41 (ground) to pin 42 (a4

line from sram u2902). Removing the solder

bridge fixed the s et.

Remove solder bridge from pins 41 and 42 of

u2901, pip micro.

Pix/Pix

CTC177 R2902 The set produces normal color on the big picture, R2902 (connecting to pin 24, U2901) was

mounted in

Pix/Pix

CTC177 R2932 Pix missing. Had video into U2901 at pins 4 and 8, Pin 6 of U2901 measured 4.3V. The DC on pin 4

was

Pix/Pix

CTC177 U2903 Video missing. The set had video to the D-PIP IC

b

The VDD to IC2901 (the D-PIP pins 11 and pin

43) s

Pix/Pix




ctc177 trace No video. Video lost at pip ic. Pins 11+12 of

u2901 had 5.4v. Pin 43 had 2.5v. Found open

trace between fb2901 and 5.4v source.

Repaired open trace.f31671sePix/Pix

CTC177AE R2925 No small picture in the pip mode. The osd would

indicate that pip had been selected, but there was

no small picture or frame for the picture. At

u2901, we found there was no sync signal or dc

voltage at pin 19. Checking through the sync

amps, q2904 and q2

R2925 in the base circuit of q2904 had been

bridged t o ground while previous solde ring of

shield tabs was performed. (loc 4-j). Removing the

short restored the small pip picture.

Pix/Pix

CTC177 R2925 Small pix missing in PIP mode. The OSD would

indic

There was no sync signal or DC voltage at pin 19

o

Pix/Pix

CTC177 CR2902 Pix flickers slightly in background. Servicer said

he found the cathode of cr2902 (off u2903 5v

regulator ic pin 2 to ground) not soldered.

Resolder cr2902F27671Pix/Pix

CTC177 R2909 Video missing Traced the video signal to U2901, but had no

outpu

Pix/Pix

CTC177 R2932 No pix. Had video into u2901 at pins 4 & 8 but

not out at pin 6 u1001,u2901,u3201 had been

replaced. Dc on. Pins 4, 6 were at 4.3v. 5 volts is

fed to a voltage divider ( r2931 and r2932 ) to the

anode of cr2904 off pin 4-u2901. We found 5v

on the anode,

Replace open r2932 10k G27687Pix/Pix




CTC177AF2 Q4105 The set intermittently won't turn on. If you have

it on and turn it off it may not come on. If you

remove the ac and count to ten reconnect the ac,

the set won't turn on. The voltage at u3101-20

was changing from 4.8 to 6.6 vdc. Found that

q4105 was leaky

Replaced q4105F26251EPower Supply

CTC177BG C7109 Coil l4101 off the secondary of the flyback had

beco me ve ry h ot. T akin g a r esis tanc e

measurement to ground there was a dead short on

the 12v e run source. Lifting jw 420 removed the

short which is used to supply 12v to the tuner.

Upon closer inspection a

Removing the solder splash across c7109 resolved

the problem.

G27341wk Power Supply

CTC177AM2 C4135 U4101 would short out. After replacement the set

ran for about 5 minutes but on bright scenes the

picture would p ull in. T his caused the regula tor

chip u4101 to blow out again. After replacing

u4101 we found that the regulated b+ was being

sucked down and

Replacement of c4135 resolved the problemG27304DTPower Supply

CTC177 CR4104 This set had weak, transparent osd like has been

reported before, with the add. symptom of no

video muting at channel change. It was possible to

see the hor. freq. Change and lock back in as

channels were changed. Cr4104 was zenering at

5vdc and the 5v st

Replace cr4104F25190sePower Supply

CTC177 CR4104 No on screen display the 5 volt standby was

reading 4.7 volts which is low but everything else

was working on the set.

Cr4104 which is 5.6 volt diode was reg. At 5 volts.F27150SEPower Supply

ctc177af3 cr4109 Reg b+ would change from 140vdc to 120vdc. The

pix wou ld cha nge from a full siz e pict ure to a

postag e stam p pict ure. I t woul d chan ge siz es

slowly.

Found cr4109 defective.Power Supply




CTC177 R4105 The set makes a buzzing sound in the off mode.

Reg b+ is high the set worked ok but when you

turn it off the regulated b+ measured 215 vdc at

t4401-3. The servicer had replaced c4103. The

voltage at u4101-2 & 6 was about right. On pin 6

side of c4102 the

Resoldered r4105.F26631SEPower Supply

CTC177AF C4108 Piecrusting- sometimes in bands, sometimes over

whole picture. Checking power supplies, tech

found c4108 at 100uf, should be 1000uf.

Replacement of c4108 cured problem.F26251ETPower Supply

CTC177 C4108 Piecrusting. Sometimes in bands, sometimes over

th

Checking power supplies, found C4108 at 100uf -

sh

Power Supply

CTC177aa3 JC403/411 Dead set. Had no supply to u1001 pin 22. Found a

open between jc403 and jc411, which is supplying

the 12volts stby 2a to pin 22 of u1001.

Replaced defective jc411.Power Supply

CTC177 CR4115 Dead set. All standby voltages were key. Micro

was working okay. Pin 22 of u1001 was at .4 vdc.

Found diode cr4115 off pin 22 was shorted.31GT657Power Supply

CTC177AD C4127 Regulated 140.5v goes to 300 volts and vents

c4107. Tech found c4127 value checked ok but,

esr was high.

Replaced c4127 (near u4101-1).G27341WK Power Supply




ctc177h2 cr4701 No vertical. No b+ to u4501. No 26v. Cr4701 checked good but replacement fixed set. j205 30blPower Supply

CTC177 Q4105 Remote would not function most of the time.

Ir3401

Replacement of Q4105 restored remote operation

of

F25215WTPower Supply

CTC177 FIX Dead set due to the 5 volt supply down to 2.9volts Removed R4108 and cleaned the area under the

compo

CHASSIS:Power Supply

CTC177BG L4102 Intermittently tv was dead. Corrected bad solder connection on l4102 (on the

140v line).

G27343HPPower Supply

CTC177 trace Intermittent dead, changing chans, bringing up

menus etc.

Found the foil that connects to jw447 and jw448

cracked. (jw448 is off the emitter of q4103 the 5v

stby2 source)

F27671Power Supply

CTC177 CR4701 Vertical missing. There was no B+ to U4501 and

no

CR4701 checked good, but was defective.

Replacing

Power Supply




CTC177 COIL WIR Streaks in pix. Digital noise in picture. The degaussing coil wires were laying too close toPower Supply

CTC177 C4105 Vertical was pulled down approximately one inch

fr

The 140V line was noisy. C4105 was defective.

Repl

Power Supply

CTC177 C4103 Dead set.the secondary of the power supply (the

143volt especial ly) was over 250 volts. checking

the circuit at the chopper regulator ic, found an

open capacitor at pin 6, u4101.

Replacement of c4103 fixed the set.F26631SEPower Supply

CTC177 C4103 Dead set c4107 vented. Reg 140 line high (over

200) while checking the feed back circuit of the

regulator he noticed that c4103 off pin 6 of

u4101 was missing. Replacement brought 140 v

line down to normal.

Replace missing c4103F27671SEPower Supply

CTC177 C4135 Dead set. U4101 would short. After replacing

U4101

The regulated B+ was being pulled low by a leaky CPower Supply

CTC177 Q4105 Intermittently, the set Won't turn on. The voltage at U3101 pin 20 was changing from

4.8V

Power Supply




CTC177 C7109 Dead set. Coil L4101 off the secondary of the flyback had

be

Power Supply

CTC177 CR4703 Dead set. The 12V supply was down to 9VDC. The 5V

standby wa

Power Supply

CTC177 CR4109 Picture changes size. The picture would change fro Regulated B+ was changing from 140VDC to

120VDC. C

Power Supply

CTC177 TRACE No vertical deflection, Line toward the bottom of Repaired open trace between r4106 & c of q4101.Power Supply

ctc177aa2 cr4106 U4101 shorts from pin 11 to 9 immediately after

plug ged i n. Found that the 1 40 vo lt li ne on the

secondary was shorted to ground. Cr4106 wasshorted.

Replaced cr4106. I have had this diode bad before,

but th is is the f irst o ne th at wa s cau sing t he

regulator ic to short.

25gt506Power Supply

CTC177 CR4106, U Dead set U4101 shorts from pin 11 to pin 9 immediately

afte

Power Supply




CTC177 C4124 Dead set. Set ticks when turned on. The 140V is normal until set is turned on. Then itPower Supply

CTC177 CR4104 OSD looks transparent. Found B+ on U3201 was at 3.8V and CR4104

zenering

Power Supply

ctc177cc c4124 Set tics when turned on. The 140v is ok until

turned on. Then it pulses between 100v and 140v.

Looking at the waveform at pin 3 of t4101 we

saw it to be normal in stand by and it would make

an attempt to shift towards the run waveform but

quit half way t

Found c4124 off of u4101 pin 7 to be poorly

soldered at one end. Soldering the cap repaired the

unit.

31gt657Power Supply

CTC177 C4119 Tuner would not tune channels 14, 15, 16, 17, or 3 Tuner voltage would only get as high as 9.8V. ThePower Supply

CTC177BE T4101 Buzzing sound heard from the set in the standby

mode. At 110vac, standby b+ measured 189v at

cr4106 cathode. Scoping the anode of cr4106, thetechnician described the waveform as a pulse

followed by a ringing. With pin 12 of t4101

unsoldered, the buzzing

Substituting t4101 from another chassis restored

normal operation.

25GT506Power Supply

CTC177BE Q4105 Dead. The vdd on u3101-20 measured 2.5v and

the reset pin 1 was 5.4 volts. Voltage on q4105-b

measured 5.4v, but the emitter was 2.5v.

Replaced q4105 five volt regulator.F27631SFPower Supply




CTC177 L2704 No vertical, servicer had replaced u4501 (vert

output) and rn 4501. On rn4501 (7) the 7.6v

source was missing. Measuring the q4101 (e) 7.6v

reg., There was 7.6v present but it was not there

on one side of l2704. Using an ohm meter l2704

checked open.

Replace l2704Power Supply

CTC177 CR3111 Dead tech had found open connection at tuner

shield near e116 and repaired a ll shield grounds.

The tv was still dead. The 12v stby line was at 0v.

The resistance to ground on the line was less than

1 ohm. Following the 12v stby line and unloa ding

various

This diode is not on our ctc177 prop, only on the

commercial chassis. Clearing the solder bridge

returned operation to normal.

25GH350Power Supply

CTC177AF3 R4135 C4105 vents. The reg b+ is 300 volts. Found R4135 open. Replacement restored

operation.

F27252GYFE1Power Supply

ctc177aa CR4101 Osd looks transparent. Found b+ on u3201 at

3.8v and cr4104 zenering at 4.6v. Heating cr4104

caused the osd to dissappear.

Replaced cr4104.Power Supply

CTC177 FB4110 Intermittent tuner, no picture or sound with

snow. Voltage on collector of q7401 dropped to

zero when the tuner signal disappeared. Tracingwe found we were losing the 33v to the tuner.

Corrected bad solder connection on fb4110 at 19i.F25190Power Supply

CTC177 C4127 High reg B+ Regulated 140.5V goes to 300V and vents C4107.

Fou

Power Supply




CTC177 CBA TRAC Dead set. When attempting to turn the set on,

U310

The DC input to U4102 was 15V and had 40Vp-p

when

Power Supply

CTC177 CR4104 No osd, no remote response, picture and sound ok.

But, horizontal sync takes a while to lock up

after channel change. Voltage at cathode of

cr4104 for 5v standby measured 4.8 volts.

Replaced cr4104.F26633Power Supply

CTC177 CR4704 Set had no vertical and no audio. Cr4704 off pin 9

of the ihvt was shorted and r4702 and r4517 were

open or stressed.

Replaced cr4704, r4702, r451727GT613Power Supply

CTC177 Digital noise or streaks in pix Degaussing coil wires too close to tuner. Redress

wires.

Power Supply

ctc177af c4119 No channels 14, 15, 16, 17 or 32+. Tune volts

would only get as high as 9.8v. 33v line was 10.8v

by pr oces s of elim inati on foun d c41 19 to beleaky.

Replaced c4119 and repaired set.25gt522Power Supply

CTC177 CR4704,R4 The set would Shutdown. It appeared to be an

over-

Traced the fault to a shorted CR4704 (12V run

sour

Power Supply




CTC177 R4104 Dead set All voltages on U4101 were at zero except pins

11

Power Supply

CTC177 R4104 Dead. All voltages on u4101 were near zero

except pins 11 & 12 which were 168 volts.

Replaced open r4104 (u4101-4).F25190SEPower Supply

CTC177 C4103 Dead set C4107 had vented. The regulated 140 line was

high

Power Supply

CTC177 C4103 The set had a high pitched Squeal when the TV

was

When the set is in standby, the 143 volts at the sPower Supply

CTC177 Q4105 No osd. B+ to pin 20 of u3101 was low (3.8) and

checking back at the 5v standby supply we found

q4105 had a b-e short.

Replace q4105F25190SEPower Supply

ctc177 q4105 2 seconds after turn on the set shuts down.

Repeats when power pressed again. Only pulses

one time and quits. Found reset line at 4.8v. 5v

line was at 3.3v. Q4105 had 3.3v at b and c.

Replaced q4105 with e to b short and repaired the

unit.

25gt542Power Supply




CTC177 CBA Dead set int. When changing channels, bringing up The foil that connects to JW447 and JW448 was

crac

Power Supply

CTC177 CR4704 Set shuts down at turn. found it to be over current

shutdown. Traced the fault to a shorted cr4704

(12v run source). have found r4702 and r4517

opened as well. the set worked fine after these

parts were replaced.

Replaced cr4704, r4702, r4517.27GT613Power Supply

CTC177 U2903 Video missing. OSD normal. The video was traced from U1001 to the PIP chip

(U

Power Supply

CTC177 R4104 Dead set following a brief power disruption. The p R4104 (at pin 4,U4101) was open. Replacing

R4104 r

Power Supply

CTC177 Q4105 OSD missing The B+ to pin 20 of U3101 was low (3.8V) and

check

Power Supply

CTC177 C4108 Dead set The 12V standby voltage was low on U4102 pin 3

in

Power Supply




CTC177 R4517 Vertical problems and/or Snowy pix. The picture would become snowy and display

various

Power Supply

CTC177 C4706 Repeat failure of cr4704. Replacement diode only

lasts a few seconds. Found open c4706.

Replaced c4706.Power Supply

CTC177 CR4106 Dead set dead set, no 140 regulated b+. Found

cr4106 the 140vdc rectif ier shorted

Replaced cr4106F27631SFPower Supply

CTC177 CR4704 The set had no Vertical and the Audio missing. CR4707 off of pin 9 of the IHVT was shorted and

R4

Power Supply

CTC177 R4104 Dead. All voltages on u4101 were zero except

pins 11 and 1 2 had 167 volt s. Fo und r410 4 op en,

not supplying the start up voltage to pin 4 ofu4101.

Replaced r4104F25190Power Supply

CTC177 CR4104 Very weak osd the picture was very good, you

could just see the osd. The brightness control

would control the picture but the osd didn't

change. The voltage at the cathode of cr4104 was

4.9 vdc it should have been 5.6 vdc

Replaced cr4104F27150SEPower Supply




CTC177 Q4105 Two seconds after turn on the set Shutdown. The

fa

The reset line was at 4.8V. The 5V line was at 3.3Power Supply

CTC177 CBA OSD missing The base of Q2701 had a 0.5Vp-p signal with no

gai

Power Supply

CTC177 CR4104 No osd u3201-8 voltage was down to 4.2 vdc the

source of the voltag e is clamped cr4104 in the

base of q4 103. Th e 5.6 volt zenier diode was 5 vdc

Replaced cr4104Power Supply

CTC177 CR4106 Dead set There was no 140 regulated B+. CR4106 (the

140VDC

Power Supply

CTC177 C4103 Buzz from the set when in the standby mode. The waveforms were not as they should be (very

dis

Power Supply

ctc177af c4105 Vertical down 1" from top. Foun 140v line noisy. Replaced c4105 to repair set.25gt522Power Supply




CTC177 R4129 Dead set The voltage at pin 4 of U4101 was at 16VDC and

pin

Power Supply

ctc177 e116 Dead. Q4105 + 3 had 2.5v e. U4102 had 10v pin

1 and 7v pin 3. Subbed in our own 12v on pin 3

of u4102 with set unplugged. Found 7v on q4105 e

and 7.5v b. Cr4104 had 7.5v cathode and 2v

anode. All grounds on the tuner had been re worked

but the pad at e116

A jumper from e116 to tuner shield fixed the set.f25190sePower Supply

CTC177 E116 Dead set Q4105 had 2.5V on the emitter. U4102 had 10V

on pi

Power Supply

ctc177 R4129 Dead set voltage at pin 4 of u4101 was at 16vdc

and pin5 of u4101 was also at 16vdc.

Replaced open r4129 100k resistor Power Supply

ctc177 c4103 Set squeals when turned off. Found c4103 with

one end not soldered. C4103 is located off of pin

6 of u4101.

Soldering c4103 repaired set.f27671sePower Supply

CTC177 CR4703 Dead. 12v supply down to 9vdc. 5v standby down

to 3vdc

Found cr4703 leaky. (off pin 10 t4401)Power Supply




CTC177AF C4124 Tv makes ticking noise after pressing power

butt on and canno t be turn ed o ff. Found 140v to

pin 3 of ih vt cy clin g be twee n 100 and 125 volts .

Leaving tv turned off the regulated b+ was 135v

which normally measures 146 volts.

Replaced open c4124 (u4101-7).25GT522Power Supply

CTC177 CR4104 The set had very weak OSD. The picture was very

go

The voltage at the cathode of CR4104 was

4.9VDC. I

Power Supply

ctc177 trace No video no audio. Screen was black. R4517 had

12v on one side, 5v on the other, was hot and

smelled funny. U4501 had 1.5v on pin 5. Rn4501

had 5v on pin 5 and 0v on pin 7. We floated pin 5

of u4501 and voltages came up except the 7.5v.

The problem was t

Repair of trace returned set to normal.g26685wk Power Supply

CTC177 C4127 When plugging the set in after it had been

unplugged overnight the power supply would cycle

3 times until it would finally run in standby.

C4127 which is located off from pin 1 of u4101

was the cause.

Replacement of c4127 resolved the problem.Power Supply

CTC177 c4108 Dead set. Found 12v standby voltage low on

u4102 pin 3 in the power supply circuit. Input

voltage on u4102 pin 1 should be between 18 and20vdc. Input level was down to 11.3 with ac level

of about 2v p-p.

Replaced open c4108Power Supply

CTC177 COPPER T Video missing/Audio missing. The screen was black. R4517 had 12V on one side and 5V on the other.

R45

Power Supply




CTC177 R4136/C41 C4107 vents and reg b+ at 400vdc c4107 open

and the regulated b+ about 400 vdc. R4136 which

is only found in the later schematics. This is a smd

located at 19n on cba. (10 ohms) was open.

Replaced r4136Power Supply

ctc177 trace No osd base of q2701 had .5v p-p signal with no

gain to the emitter all the dc voltage levels on

q2701 where ok.. 7.6v supply to r2712 was at

9.6v. Found open trace between r4119 and cr4101.

Restored trace between r4119 and cr4101Power Supply

CTC177 CR4104 OSD inop The 5 volt standby was 4.7 volts. Everything elsePower Supply

CTC177 CR3111 Dead set The set had an open connection at the tuner shieldPower Supply

CTC177 R4104 Dead set following brief power disruption.the

power supply was complet ely dead.fo und an open

r4104(at pin 4,u4101). The servicer has seen atleast 8 to 9 units with the same fault.

Replacement of r4104 in each case repaired the

set.

Power Supply

CTC177 C4107 Horizontal jitter and the pic pulls when the

brigh tness goes u p unit h ad hor izont al jit ter and

the picture would pull in on the side as the

brig htnes s goes up. Found that c410 7 on the

regulate d b+ had and open lead. (same as an open

capacitor.)

Replaced c4107G27685HPPower Supply




CTC177 R4119 Vertical would intermittently drop down. found

7.6 run source varying at pin 32, u1001.

Resolder r4119 (off the base of q4101,7.6 volt

regulator).

Power Supply

CTC177 CR4104 OSD missing/no Remote response. The picture

and so

The voltage at the cathode of CR4104 (for 5V

stand

Power Supply

CTC177 C4109 Squeals at plug in, servicer had replaced u4101 for

a dead set. If unit was left plugged in u4101 would

fail. Resistance checks didn't show a fault. With

the regulator bypassed and ac set to 25 volts

c4109 started at arc and smoke as the ac was

increased.

Replace c4109 in regulator circuit.Power Supply

CTC177 C4007 Standby voltages high, 140 volt was at 180 volts.

Servicer said the raw b+ had a lot of trash on the

line. Jumping out c4007 cleaned up the line and

lowered the b+ to 140 volts

Replace c4007Power Supply

CTC177 CR4104 OSD missing U3201 pin 8 voltage was down to 4.2VDC. The

source

Power Supply

CTC177 C4107 Horiz jitter and the Pix pulling in when the brigh C4107 on the regulated B+ had an open lead.

(Same

Power Supply




CTC177 R4135 Plugging in ac c4105 and c4107 overheat. Replaced open r4135 (t4101-7).G26638Power Supply

CTC177 T4101 Buzz in standby mode. At 110VAC, standby B+ measured 189V at

CR4106 cath

Power Supply

CTC177BF CR4109 Poor regulation. Picture width would decrease with

high video content in picture reg. B+ would vary

from 140vdc to as low as 123vdc. U4101 had

been chan ged. Check ing compone nts in regu lator

circuit, cr4109 checked leaky in the forwarddirection. Tech repl

Replacement of cr4109.F27671SEPower Supply

ctc177 c4103 Buzz from set in stand-by mode. Wave forms

were not as they should be. Very distorted. Voltage

on pin 2 of u4101 was slightly low. Very little

waveform.

Inspection showed very poor solder connections

on c4103. Resoldered. No buzz

Power Supply

CTC177 T4101 Low regulated b+ T4101 pin 1 to pin 3 a high resistance.Regulator

CTC177 IR RECEIV After the set powers on, the Channels scan upward. There were signals out of pin 1 of U3101. The

volt

Remote Con




CTC177 IR3401 Set would turn on and go into autoprograming and

t

Jumped 4.6 volts to pin 1 of u3101 and the set wor CHASSIS:Remote Control

CTC177AF2 IR After the set powers on, the set started to scan up

channels. Found signals out of ir receiver at pin

1,u3101 and the voltage at pin 1 was 0v. pin 1

should be 4.6v. isolated problem to the ir receiver.

Replacement of the ir receiver.Remote Control

CTC177 Q5004 No video. Original problem was dead set, with

defective ihvt. Servicer had replaced u3201 and

u3101 but couldn't get any on screen display to set

up the alignments. Servicer had flat black screen

with audio and no osd. Checking crt setup wefound that th

Found b-e open on q5004 on kine socket cbaRGB

CTC177 Q5001 Color appears to be breathing,with the tint

changing. Scoping signals from the t chip did not

reveal any problems. Found that the signals at the

collector of q5001 were varying as the condition

symptom developed.

Resoldering q5001 on the kine drive cba.RGB

CTC177 YOKE The set would Squeal when turned on. The horizontal output, Q4401, was shorted when

the

RGB

CTC177 Q5001 Color changes and the tint changes. Scoping signals from the T chip did not reveal anyRGB




CTC177AA3 R5012 No red. Resistor r5012 in the emitter of red drive

q5001 had increased from 130 ohms to over 2000

ohms. Red drive transistor was turn off.

Replaced resistor r5012.RGB

CTC177 Q5004 Bright screen with retrace. Crt had been replaced

the cathodes measured between 40 to 50 vdc. We

went to q5003 the collector was 41, base 2.1 and

emitter 1.5. Then we checked q5004 the emitter

base and coll ector were all 0 v dc. (sh orted)

Replaced q5004F25651BLRGB

ctc177 c5004 Pix too bright. Could not get pix brightness down

using the screen control. Found c5004 off of base

of q5004 shorted.

Replace q5004.RGB

CTC177 Q2701 Green missing in menus. Q2701 (G-OSD driver) had correct waveform at

base

Special Effects

CTC177 Q3303 Closed caption missing. OSD was normal. Found no video at U3101 pin 13. Tracing from

U1001

Special Effects

CTC177 C2308 Pix snowy/Horiz sync missing. Pin 6 on U1001 was down to 2VDC. Found C2308

was c

Sync




CTC177 C2308 No horizontal sync and snowy pix. Pin 6 on

u1001 down to 2vdc. Found c2308 cracked.

Replace c2308 . This cap is mounted on the

chassis where the rails contact the chassis. Sliding

the chassis in and out can cause the cap to become

cracked.

Sync

CTC177 U3201 Red distorted/Green smears U3201 was defective. Replacing U3201 repaired

the

System Control

CTC177 R2711, C27 No Autoprogramming in the cable mode. In the

off-a

Checking Q3301 off pin 39 of U3101, there was

only

System Control

CTC177BD C3103 Chassis will not power on. all standby voltages

checked normal. Found the voltage on pin 7,

u3101 1.9 volts. it should be 4.7 volts. Traced

fault to a leaky c3103.

Replacement of c3103.System Control

CTC177 R3132, R31 Dead set. Reset voltage was missing at U3101 pin

1

R3132 and R3133 were open. Replacing R3132

and R31

System Control

CTC177 connection The video and audio will intermittently go out,

and change channels by itself. this condition does

not last. the set may clear up and work for

extended periods. The shield that borders the

micro had a tab that was not soldered

To the board at location j3.System Control




ctc177be c3102 Dead. U3101 pin 5= 4.5v, pin 15 +16 = 2.5v.

U3201 pin 5 = 2.5v, pin 6 = 0v. Pin 6 of u3201

measured 300 ohms to ground. Found shorted

c3102. Removed and set worked.

Replace c3102.f27351wnSystem Control

CTC177AM2 C3113 Intermittently the degauss relay would chatter. Found c3113 (off pin 1 of u3101) the ground end

not soldered.

G25361BK System Control

CTC177 TRACE Video missing/OSD missing The horizontal pulse to U3101 pin 26 was

missing.

System Control

CTC177 U3201 Video int U2901 would lose all voltages on all pins except 2System Control

CTC177 C3310 OSD rolling vertically. The waveforms at pins 24 and 25 of U3101 were

norm

System Control

CTC177 Q3101, Q3 Dead set. All voltages on U3101 were normal. No data

appeare

System Control




CTC177 JW408, JW Dead set. U3101 and U3201 had been replaced. Pins 5 and 6 of U3201 measured 2.5VDC. There

was a

System Control

ctc177 u3201 No vertical. Line across screen was dim. Pin 16

of u1001 was at 7v. No output on pin 17.

Voltages on u4501 looked ok.

Replacement of u3201 repaired the set.25gt536System Control

CTC177 U2901, U3 External Video missing. Normal tuner video was

pre

U2901 was defective. Replacing U2901 still did

no t

System Control

CTC177 U3201 The OSD was stretched and shifted to the left. Pin 6 of U3201 (data line) was compressed to

3.5Vp

System Control

CTC177 U3101 Dead set. U3201 and U3101 would intialize

prop erly

All the voltages around U1001, U3201 and

U3101 wer

System Control

CTC177 C3307 OSD missing U1001 had waveforms at pins 40, 41 and 42 when

the

System Control




CTC177 U1001 OSD red. The channel number and volume

indicator w

U1001 pin 40 (red OSD input) waveform was

normal,

System Control

CTC177BE Solder No osd, u1001 had waveforms at pins 40, 41 and

42 when menu was button was pushed. Checked

pin 3 9 of u 1001 and found no ch ange at al l. Had

servicer go to pin 22 of u3101 and he noticed a

solder bridge across c3307. Removing the short

returned normal osd.

Remove solder bridge from c3307. N\ASystem Control

CTC177 Q3301 Autoprogram inop. U3101 pin 39 had no sync pulse. Q3301 had a

brok en

System Control

CTC177 U3101 Dead set The B+ and clock signal was normal. The clock

and

System Control

CTC177 U3201 Spanish mode could not be turned off. U3201 was defective. Replacing U3201 repaired

the

System Control

CTC177 U3101 Pix red on some channels. Other channels were

fine

U3101 was defective. Replacing U3101 repaired

the

System Control




CTC177 SOLDER S Dead set/Won't power on. Standby supply was

normal

Followed the problem to the enable line. Pin 14 of System Control

ctc177 u3101 Dead b+ and clock ok. Clock and data lines

constantly active when we checked but servicer

said he checked the data later and it was missing.

Replacement of u3101 repaired set.f25190seSystem Control

CTC177 T4401 The TV would Power off/on intermittently. Repairing bad solder connections on T4401

(IHVT) p

System Control

CTC177 TRACE Controls inop/Video missing/Audio missing.

U3201,

U1001 pins 53 and 54 were at 4.7V, but pin 52

was

System Control

CTC177 CR3302 OSD rolling. There was no sync at pin 25 of U3101. Replacing

a

System Control

ctc177 r3316 No closed caption. Osd ok. Found video on pin

13 of u3101 ok. Pin 25 of u3101 had 1.5v instead

of .25 with 21v p-p instead of 5vp-p. Found and

replaced an open r3316.

Replacement of r3316 off of pin 25 repaired set.f25651blSystem Control




ctc177 q3101 Dead set. Reset line on u3101 0v. Replaced leaky q3101 reset transistor.27gt613System Control

CTC177 trace Intermittent shutdown. Intermittent snow at

times,channels changing.

Repair broken foil pattern at location e116 to

tuner shield ground foil.have seen many of these

chassis with same faults.

F25190SESystem Control

CTC177 trace Keyboard not working. If you lift the shunt

capacitors the keyboard would function inspection

of the cba revealed the trace at 17j where r3332,

c3303 & r3314 solder in was lifted up and twisted

and shorted to the listed components. Redress andrepair of

Repaired cba trace at 17j27gt613System Control

CTC177 JW436, R7 Tuning missing in cable mode. OSD missing. Set

had

Found Q7403 and Q7404 were leaky. Replacing

them r

System Control

CTC177 U3201 Audio missing. The Speaker Mute was activated. U3101-29 was high at 5VDC activating the

speaker m

System Control

CTC177 Q3101 Dead set Pin 16 of IC U3101 was at 0VDC. Pin 15 was at

4.8V

System Control




CTC177 R3104 Dead set unless power button is pressed immediatel Found R3104 was open. Replacing R3104 restored

nor

System Control

CTC177 C3103 Dead set The microprocessor and EEPROM had been

replaced fo

System Control

CTC177 U3201 No sound. With service adjustments tech was able

to correct horizontal frequency, vertical size and

vertical dc. No sound was caused by 5v on u3101-

29 spkr mute.

Replaced u3201.25GT506System Control

CTC177 connection No autoprograming in cable mode. In air mode the

unit programmed fine. Checking q3301 off pin

39 of u3101 found only 1.2 vdc on the collector.

Checking the base of q3301 for signal we had

none. Following the circuit back to r2711 and

c2718 found a solder

Removal of the solder bridge on r2711 and c2718

repaired the set. During resoldering of the ground

tabs the servicer could cause this problem.

F25251WNSystem Control

CTC177 Q3305 OSD missing There was no signal at U3101-18 and only 1 volt

p-

System Control

CTC177 BROKEN F Int shutdown. Intermittent snow at times.

Channels

Repairing a broken foil pattern at location E116 tSystem Control




CTC177 U3201 Vertical foldover at top. Bottom was pulled up 3 i Pin 15 of IC4501 was at 18V and pin 16 of

U1001 wa

System Control

CTC177 U3201 Vertical missing. Both U1000 and U4501 had both been replaced.

U3201

System Control

CTC177 U3201 Very slow Channel change in the cable mode. Off-

ai

The AGC at pin 12 of U1001 would wander high

and l

System Control

CTC177 SW3410 Dead set-- standby supplies normal, no data at

u3101-15/16. U3101 had been replaced, and

grounds repaired. Checking u3101 pins 5-8: 5, 7, 8

were normal at 0,5,5 vdc but 6 was .6vdc when it

should have been 5vdc. Lifting pin 1 of sw3410

allowed pin 6 to g

Replaced leaky sw3410F25651blSystem Control

CTC177 C3312 Remote inop Pin 3 of U3101 was at 2.5VDC. C3312 (off of pin

3

System Control

CTC177 U3201 The set Powers on when AC is applied. Pressing

the

Replacing the EEPROM, U3201, repaired the set.System Control




CTC177 R3316 No closed caption. The OSD operated normally. The video on pin 13 of U3101 was normal. Pin

25 of

System Control

CTC177 U3201 Bar in pix on UHF channel 50 only. Found U3201 was defective. Replacing U3201

repaire

System Control

CTC177 U3201 The set picks up only two channels, there are no

menu functions , there is no color. checking the

vcc at u3201 checked normal. Typical clock and

data activity present as compared to other sets.

Replacement of u3201.the tech had confirmed

two repairs of the same chassis with the same

prob lem.

F27671System Control

CTC177 C3126 Dead set Micro was not running. The reset line was low.

Th e

System Control

CTC177 R3120 Dead set Found no reset voltage on pin 1 of U3101. Traced

t

System Control

CTC177 U3201 Tuning inop. The set picks up only two channels.

T

The VCC at U3201 checked normal. Typical

clock and

System Control




ctc177 c3104 Pushing the menu button gives you part of the set-

up menu. Pushing it again makes the menu go

away, instead of running thru the various

functions. Found that shorting pin 8 of u3101

directly to ground would give us the proper menu.

Lifted the smd capacit

Replaced leaky c3104.x25101gsSystem Control

CTC177 C3201 Dead set Pin 5 of U3101 was at 4.5 volts. U3101 and

U3201 h

System Control

CTC177 CR3302 Osd rolling. No sync at pin 25 of u3101. Replaced shorted cr3302 off pin 25 of micro.

This is a three legged smd at location i-13.

System Control

CTC177 C3113 Degauss relay chatters intermittently. Found C3113 (off pin 1 of U3101) had a bad

solder

System Control

CTC177 C3103 Won't power on. All standby voltages checked

norma

Found the voltage on pin 7 of U3101 was at 1.9V,

b

System Control

CTC177 U3101 OSD compressed. Replacing the EEPROM did not

corre

Found U3101 was defective. Replacing U3101

repaire

System Control




CTC177 C3102 Dead set U3101 pin 5 was at 4.5V, pins 15 and 16 were

bot h

System Control

CTC177 U3101 OSD malfunction. The channel 4 (OSD) flashes

on an

Replacing U3101 repaired the set.System Control

CTC177 CBA OSD inop Horizontal and vertical sync was present into

U310

System Control

CTC177 ALIGNME Vertical foldover at top and stretched out on the Pin 5 of U4501 was at 19 volts. Entered the se rvicSystem Control

CTC177 C3104 Menus missing. Pushing the menu button produced

pa

Shorting pin 8 of U3101 directly to ground would

p

System Control

CTC177 C2708 Intermittent Red components of OSD. C2708, off of U1001 pin 40, was defective.

Replaci

System Control




CTC177 U3201 No Vertical. The picture displayed only a line acr Pin 16 of U1001 was at 7V. There was no output

on

System Control

CTC177 C3115 Dead set. The set will not turn on. The oscillator at U3101 was not operating

prop erly

System Control

CTC177 U3201 The set had no Vertical deflection. The T Chip

had

Lifted JW322 and applied an external drive to

RN45

System Control

CTC177 U3201 Vertical foldover at top and the bottom was pulled Pin 5 of IC4501 measured 18V and pin 16 of

U1001 w

System Control

CTC177 C3109 Dead set. Replaced the eeprom twice and the

microprocessor once. Checking the clock and data

lines at pins 15 & 16 of u3101 saw no activity.

The oscillator was running on pins 41 & 42.

Measured dc voltage at pins 5 & 6 of the micro,

found pin 6 down to

Removing c3109 in the circuit off pin 6 of u3101

brou ght t he v oltag e up to 4. 7v and al lowed the s et

to turn on. Replace c3109.

25GC710System Control

CTC177 U3201 On screen display is stretched and shifted to left.

Pin 6 of u3201 (data line) was compressed to

3.5vpp pulses lifting pin 6 restored to 5.1vpp.

Replacement of u3201 restored proper operation.27GT614System Control




CTC177 EEPROM PIP pix was missing. The EEPROM (U3201) had

been r

Checking the service mode parameters for PIP

(20,

System Control

CTC177 VERT ADJ Intermittent Vertical foldover at the bottom one t Changing the Vertical Adjustments in the SVC

menu

System Control

CTC177 connection Intermittently tv would go off than back on, but

all customer controls (color, brightness, contrast

& etc.) Are on the left end.

Corrected bad solder connections on t4401 (ihvt)

pins 1 & 2 .

25GT506System Control

CTC177 Q3101 Dead set The reset line on U3101 was 0V. Replacing a

leaky

System Control

CTC177 Q4105 Dead set U3101 pin 20 measured 2.5V and the reset pin 1

was

System Control

CTC177 U3201 Dead set. High voltage came up as soon as AC was

a

Checking voltage at the front panel inputs to

U310

System Control




CTC177 U3101 PIN Dead set Pin 5 of U3101 measured 2.5 volts, should have

bee

System Control

CTC177 C3103 Volume down from front panel would make the

volume go up. With the remote the volume would

work okay. The micro had been change by the

servicer before he called. Pin 7 u3101 was at 2.2

vdc instead of 4.5 vdc. C3103 was pulling the pin

low.

Replace c3103G2766SWK System Control

ctc177 U3201 Tv was stuck in the Spanish mode. There is not a

Spanish option in the menu.

Replaced u3201 and menus went back to English.G27613System Control

CTC177AA U3201 Had no vert. U1001 had been replaced. Lifted

jw322 and d rive rn45 01 wi th a b&k a naly zer to

get sweep. Once he had sweep he could get the

service menu. When he went to vert centering in

the menu it was at 238 instead of a value between

00 and 15.

Aligned Vertical centering25GT506System Control

CTC177 U3201 Set powers on with ac applied. Pressing the power

butto n caused the d ispla y to go of f. Th e pic ture

remains. Pressing the power button again caused

the picture to go away, the degauss relay would

energize. 3-4 seconds later, the picture would

return.

Replacing the eeprom, u3201, restored normal

operation to the set.

F25651BLSystem Control

CTC177AD C3310 Two narrow menus appear beside each other when

called up. Tech noticed distorted signals at u3101

pins 17, 1 8 & 1 9. Un der clos e ins pec tion , c33 10

off u3101-27 (vco) was found cracked.

Replacement of c3310 restored normal menus.System Control




CTC177 connection Tv wont turn on with power button on set, but

will with remote. Otherwise tv worked.

Removed solder splash near power switch s3411

on front panel assembly.

G27343System Control

ctc177 u3201 Very slow channel change in cable mode, air ok.

The tv would take 3 seconds to find a channel

when in cable mode. Agc at pin 12 of u1001 would

wander high and low a couple of times before tv

would lock on channel.

Changing u3201 repaired set.f27671seSystem Control

CTC177 C3310 Menu is doubled. U3101 pins 17, 18 and 19 had distorted signals. C3System Control

CTC177 Solder No autoprograming. U3101 pin 39 had no sync

pulse. Found q 3301 was not solder ed at the

collector. Resoldering q3301 returned

autoprograming.

Resoldered q3301.System Control

CTC177 C3115 Dead set. will not turn on.the oscillator at u3101

was not operating normal.the signal at pin 41 was

weak. found c3115 had changed value from 56pf

down to 8pf.


ctc177ae U3101 Compressed osd characters. Replacing the eeprom

did not help.

Replaced defective u3101.25gc752System Control




ctc177bh2 trace No video or osd. The horizontal pulse to u3101

pin 26 ( chassis family 2 ) was mis sing. Foun d

open trace from pin 8 of the ihvt to r3343 to the

emitter of q3305.

Repaired open trace.System Control

CTC177 C3106 Unit would turn on if you hit the volume up button Change c3106.System Control

CTC177 TRACE No control with remote. Remote would operate

other

Placed a jumper between r3301 & jw453 and

remote o

System Control

CTC177 U2901 Tv had normal video, when you try to switch to

external video, you would still get tv video from

the tuner. the tech first changed u3201, no

improvement.then u2901 was replaced, no help.

Finally he replaced u3201 again and the set was

fixed.it appears tha

Replacement of u3201, u2901.System Control

ctc177 u3201 Intermittent video. U2901 would loose all

voltages on all pins except 20,21,22 an b+ pins.

The ic was changed. Video could be brought back

by ju mpin g out the c hip. There was never any p ip

functions. Symptom could come and go at any

time.

Replacing u3201 repaired the set.f25190seSystem Control

CTC177 Alignment Vertical is folded over at the top and stretched out

on the bottom. Servicer had already replaced

u4501 and u1001. Pin 5 of u4501 was at 19 volts.

Entered the service menu and found p05 at v00

(vertical dc). Ran the value up to v06 and vertical

returned t

Realign vertical settings in service menu. (have

fixed several TVs with this)

System Control




CTC177 C3310 Osd rolling vertically. there were three sets of the

same osd display. they were displayed

horizontally. checked waveforms at pins 24, 25 of

u3101 and they were fine. found noise on pin 27,

u3101, which is the vco pin.traced fault to an

open c3310.


CTC177 alignment During chan change the consumer complained of a

very intermittent vertical foldover at the bottom

1/3 of the screen. You would probably not think

anything about it because it happened so quick and

blam e it on n o syn c to the vert ica l jus t sho rtly

after ch

Align verticalSystem Control

ctc177bd r3203 Dead. Servicer found that he could turn set on if

he lifted jw 407 or jw408. With both jumpers in

the unit the data lines were at 3v dc and constant

data. Servicer noticed a brown dot on r3203 (off

of pin 5 of u3201). We put a jumper across thisresistor

Replaced r3203 repaired set.g27681ck System Control

ctc177aa3 paint Dead. Found that the dc level on pin 52 of u1001

was at 1.7v on pin 14 of u3101 it was 4.7v.

Lifting components found that the trace between

pin 52 of u10 01 and the ju mper j w443 was loa ding

the line down. Starting at jw443 we started

removing the black pa

remove paint25gt506System Control

CTC177BF JW408 Dead , servicer had replaced u3101 and u3201. On

u3201- 5, 6 there was 2.5vdc on each pin.

Servicer was instructed to lift jw408 and jw470.

When these were located servicer found a solder

splash across these jumpers.

Removed solder splash and set worked correctlySystem Control

CTC177 Q3303 No closed caption. osd was normal found no video

at u3101-13 following from u1001-44 lost at

q3304. Checking voltages we found q3304 turned

off emitter was at 5v. Found q3303 at 11.8v at all

three leads. Checking showed it to be shorted

Replace q3303.F27631System Control




ctc177 c3126 No operation. Micro not running. Reset line low.

Base q3101 .6 v. Anode of cr3102 4.8 v c athode

4.1 volts. Found c3126 shorted.

Replace c3126System Control

CTC177FE R3132 Dead set no reset at u3101-1 . R3132 82k and

r3133 100k were open.

Replaced r3132 and r3133F25671FESystem Control

CTC177 U3101 White square comes up right of center, looks like

a computer cursor.

Replace u3101F27252System Control

CTC177bh2 C3114 Set would not turn on u3101 had no clock found

c3114 was 2k to gnd

Replaced c3114F27251wnSystem Control

CTC177 U3201 Had vert fold over at top and the bottom was

pulled up 3 i nches ic4501 had b een r eplaced. Pin

5 of u4501 was at 18vdc and pin 16 u1001 was at

7.5vdc. Replaced u3201 and vertical worked

pro per ly.

Replace u3201System Control

CTC177 JC430 Brightness goes low. Speakers turned off.jc430 not

soldered

Resoldered jc430 off u3201-8F27671SESystem Control




ctc177 q3101 Dead set. Voltage at pin16 of ic 3101 is 0vdc. At

pin1 5 of ic 3 101 4.8 v dc.. The re i s no data on

pins 15 and 1 6 of u310 1. Pi n 1 o f ic 3101 is 0v dc.. .

Found q3101 shorted c-e. Replaced transistor and

set worked normally.

25gt506System Control

CTC177 SW3430 Dead unit. Checking the micro u3101 found pin 8

at .3vdc. Unsoldering the menu switch sw3430

cleared the pin.

Replace sw3430System Control

CTC177 U3101 No OSD. This is a new chassis where the OSD goes

s

Replace U3101.F25254System Control

ctc177af3 q3101+310 Dead set. Found all voltages on u3101 to be ok.

No da ta appea red when tryi ng to turn on se t. Os c

running. Only clue was pin 2 of micro (reset) was

at 5.2v instead of 5.4v. Wer momentarily ground

pin 2 and t hen s et wo uld t urn on and wo rk T he s et

went back

Replaced the reset transistors q3101 and q3102

and set was repaired.

f25251wnSystem Control

CTC177 U3201 Speaker mute is activated u3101-29 is high a

5vdc activating the speaker mute. This is caused

by u3 201.

Replace u320125GT506System Control

CTC177bg U1001 Set was dead, with 5 volts on pin 5 of u3101.

Found by lifting pin 51, 52, 53 of the u1001 t-

chip, pin 5 of u3101 would return to 0volts.

Found that pin 53 measured 327ohms to vcc pin

22.

Replaced u1001, and normal operation was

restored.

27GC901System Control




ctc177 u3201 Shaded bar in pix on channel 50 uhf only. Not all

have the bar on the same station. One was fixed

by ch angin g u73 01. U7301 did n ot fi x thi s set .

When checking tuner parameters we found that

we could run them up to 247.

Changing u3201 cleared the symptom.f25650bcSystem Control

CTC177 U3101 OSD piecrust. The set operated normally except

the

U3101 pin 21 was internally shorted to pin 26.

Rep

System Control

ctc177am r3104 Dead set unless power button is pressed

immediately after plug in. If power button is

press ed in time, the v ol up and d own, and th e

channel up down will display menu... There is no

control over the menu once it is up.. The unit cannot be powered down eit

Replaced def r3104g25361bk System Control

CTC177 C3103 Dead set. U3101 3201 had been replaced for

other reasons, after which the set was dead. No

data or clock activity on u3101 pins 15 & 16 in

the standby mode nor when trying to turn the set

on. Oscillator was running correctly. Voltages

were normal at pins

We located a technician induced short across

c3103 off pin 7. Removing it restored normal

operation. The cap is right beside a system

control shield ground tab.

N\ASystem Control

CTC177 U3201 Red colors look fuzzy, distorted and the greens

were smeary.

Replacement of u3201.System Control

CTC177BD U3201 High voltage came up as soon as ac was applied.

The power button had no effect and no picture,

sound or osd appeared. Checking voltage at the

front panel inputs to u3101, found pin 5 always

high with pins 6, 7 & 8 also high. No change of

data activity w

Replacement of the eeprom, u3201, restored

normal operation to the set.

G27687WK System Control




ctc177bh u3101 Some channels would have excessive red in pix.

Other channels were fine.

Problem was solved by replacing u3101.27gt613System Control

CTC177BG IR Remote will operate at a short distance of a few

feet. Removing the ir window allowed the remote

to operate at great distances.

Replacement of the ir window.G27341System Control

CTC177BB SOLDER Set was dead with pin 5 of u3101 measuring 2.5

volts. Should of been zero. Found pin 21 of u3101

with a bad solder connection.

Soldering pin 21 of u3101 restored pin 5 to zero

and set turned on.

System Control

CTC177 R3120 Dead set. Found no reset voltage on pin 1 of

u3101. Traced problem to open resistor, r3120

off pin 1.

Replace r3120System Control

CTC177AD C3201 Dead set. Pin 5 of u3101 was at 4.5 volts. U3101

and u3201 had both been replaced. Voltages on

pin 5 & 6 o f u32 01 we re a t 3 v olts but p in 8 was

close to zero.

Found cap. C3201 was shorted. This cap. Was off

pin 8.

System Control

ctc177am2 r3135 Intermittently set would turn on. Press again the

audio would turn off. When pressed again the

video would disappear. Intermittently the set

would go nuts when channel changed. U1001(52)

there was 4.9v and sometimes 3.7v.u3101 (14)

always had 4.9v. R3135

Replaced r3135 to repair set.g25342aSystem Control




CTC177 U7401 Dead set intermittently. Pix flashes intermittentl U3101 pins 5 and 6 measured 2.5V. U7401 pins 4

and

System Control

CTC177 R3203 Dead set. The set would turn on if JW407 or

JW408

R3203 (off of pin 5 of U3201) was defective.

Repla

System Control

CTC177 C3114, JC4 Dead set. U3101 pin 36 measured zero volts, pin 37 was at

6.

System Control

ctc177 c3312 No remote. Pin 3 of u3101 at 2.5v dc. Replacement of leaky c3312 off of pin 3 of

u3101 repaired set.

25gt522System Control

CTC177 R3135 Func cntrls inop. When buttons were pressed,

other

Pin 52 of U1001 measured 4.9V to 3.7V at times.

Pi

System Control

ctc177 N\A Menus were shown in triplicate kind of like 3

ghosts. Servicer found bad solder connection on

c3310. C3310 is at u3101 pin 27.

Resoldered c331025gc722System Control




CTC177 R3322 OSD missing. The FSW signal was present on pin 18 of U1001,

but

System Control

CTC177 EEPROM No small picture in the pip mode. The eeprom,

u3201, had been replaced for no pip functions.

After replacement of the eeprom, the small box

appeared but with no picture in it. Checking

parame ter s 20 , 21 , 22 & 23 they were al l at 00.

Adjusting the parameter values, especially

brig htnes s and contr ast, retu rned the p ip pi cture

to normal.

System Control

CTC177AA3 Trace Dead and 0 volts on u3101-2 reset pin. Measuring

voltages we found q3102 was biased on because the

base voltage wa s too low. We found 0 volt s to

r3132.

Repaired open trace between jc403 & r3132.

Tech said there is a small spot of green corrosion

on the trace.

25GT506System Control

CTC177 U7401 Dead set intermittently or Pix flashes intermitten When the set was dead, there was approximately

2.5

System Control

CTC177 Trace No on screen display- had h&v sync into u3101,

and osd signals were being generated at u3101-

17,18,19. Checked fast switch line at u3101-22

and found a change from 0vdc with no display to

.85vdc when a display key was pushed. Checked

u1001-39 fast switch

Found open trace between jw436 & r2733 in the

fast switch line between u3101-22 and u1001-39.

Repaired trace and osd was restored.

F25671System Control

ctc177 U3101 Dead set. U3201 and u3101 would initialize

prope rly. Clock and d ata l ooked goo d when the

power button was pu shed. U3201 a nd u100 1 had

been repla ced. A ll the voltag es ar ound u 1001,

u3201, and u3101 looked good.

Replaced u3101 and the set worked.System Control




CTC177 Q3305 No osd. No signal at u3101-18 and only 1 volt p-

p at pin 22. T he o sd sy nc s igna ls a t u31 01 p ins 2 4

& 25 were ok. However, the dc voltage at pin 24

measured 3.8 volts.

Replaced q3305 with emitter to collector short.F25190System Control

ctc177 u3101 Channel 4 (osd) flashes on and off. Screen is dark.

Turning up screen will reveal something like a pix

flashing on and off in the background.

Replaced u3101 and set was repaired.25gt522System Control

CTC177 TRACE Dead set The DC level on pin 52 of U1001 was at 1.7V.

Pin

System Control

CTC177AM2 JW427 No menus when pressing the front panel button.

Both the vol up and vol down buttons on the fpa

would increase volume.

Removing a solder bridge from jw427 & jw428

resolved the problem. These jumpers go to vol up,

vol down & menu switches in the fpa circuit.

G27302ATSystem Control

CTC177 r3134 Dead set, no power on.standby supply

normal.checking voltages at the cpu, found enable

line to be the problem.voltage at pin 14, u3101

was 4 volts and the voltage at pin 52, u1001 was 0

volt. Found a solder splash at one of r3134

(connected to pin 14, u31

Remove solder splash.System Control

CTC177 R7403 Tuner inop There was no change in the DC bias to Q7401-C

even

Tuning System




CTC177 C7102 Channels above 50 snowy. The tuning,

bandswitching , & agc voltag es were cor rect. On

cr7101 the voltage was 0vdc, making a resistance

measurement to ground there was a dead short.

Lifting c7102 off the pads allowed the voltage to

increase.

Replacement of c7102 resolved the problemTuning System

CTC177 COPPER T Cable tuning inop. There was no tuning of high or Resoldering a bad copper trace from the tuner IF oTuning System

CTC177ae CR7109 Would tune ch2 - ch6, rest ch7 - ch50 poor or

missing. Q7402 would switch form 12v to -.3volts

due to cr7109 being shorted.

Replaced cr7109, located in the tuner.Tuning System

CTC177AC C7132 Snowy picture on channels above chan. 6.

Voltages at u7501 pins 7, 8 & 14 were normal.

Checking the cathode voltage at cr7108, found it

remained at .4vdc. Measuring resistance to ground

at r7519 (rf primary circuit) to ground, we read

32k ohms on the side

Found a shorted c7132 toward the uhf circuit.

Replacement of the cap restored normal picture.

F25190SETuning System

CTC177 CR4303 Tuner inop. No low VHF tuning. There was zero volts on both ends of CR7303.

Repla

Tuning System

CTC177 C7134 Low VHF tuning missing. High VHF tuning was

normal

Checking the collector of Q7401 in the low band

mo

Tuning System




CTC177 R7413 Won't tune vhf channels. Uhf tunes normally.

The collector voltage at q7404 would not change

between u hv & vhf.

R7413 was open off the base q7404.Tuning System

CTC177 R7401 Snowy pix on channels 7 and up. Checking voltages at U7501 showed on pin 3 was

bel

Tuning System

CTC177 C7410 Dead set U3201 had been replaced. Pin 5 of U3201 was at

zer

Tuning System

CTC177 R7413 Set will not tune VHF channels. UHF channels are

n

The collector voltage at Q7404 would not change

be

Tuning System

CTC177BB R7514 Poor tuning ch's 30- 50. All others good. At

u7501-14 we had 15v but at cr7108 we had .34v.

R7514 at pin 14 checked good in circuit, but the

15v drop was across it. Bridging another 100k

across r7514 restored normal voltage at cr7108

and normal tuning on

Replacement of r7514.G27687WK Tuning System

CTC177 C7132 Pix snowy in channels above channel 6. Voltages at U7501 pins 7, 8 and 14 were normal.

Ch

Tuning System




CTC177AK R7415 Weak tuning channels 7-13/ 18+...q7402-c stays

at -16v. U7401- 8 switches between +12v and 0v.

R7415 between u7401-8 & q7402-b checked 10m

ohms. Replaced open r7415 & restored normal

tuning.

Replaced open r7415.25GC710Tuning System

CTC177 R7401 Pix snowy when tuned to the upper channels in

each

With channel 6 selected, the voltage was down to

1

Tuning System

CTC177 R7127 Tuner will not tune high VHF or UHF channels. Q7402 collector was switching between VHF low

and

Tuning System

CTC177 Q7401 Tuning inop. Set will only receive channel 2 until Putting cool spray on IC7401 caused unit to fail.Tuning System

CTC177 U7301 Channels missing. Cable channels 51 and above

were

U7301 was defective. Replacing U7301 repaired

the

Tuning System

CTC177 TRACE Pix snowy on some channels. Traced voltage to both sides of R7145 and found

no

Tuning System




CTC177 R7408 UHF snow/VHF missing U7501 had between 30 and 33 volts on pins 8, 14,

a

Tuning System

CTC177 U7401 Will not tune low band vhf, channel 8, channel

14 will tune in when you select channel 19.

isolated fault to u7401.

Replacement of u7401.Tuning System

CTC177 U7301 Cable channels 51 and above not working. Replacement of u7301.Tuning System

CTC177 C7408 Tuning inop U7401 pin 10 was at zero volts. Q4106 emitter

was

Tuning System

CTC177 C7110 Poor tuning, especially on channels 2- 6, 14- 17.

Q7402-c had 12v on 7- 13, 18-50, but 0v on 2-

6,etc. Found that cr7112 had 0v on the a node at

all times. Found c7110 shorted at the anode of

cr7112. Replacing c7110 restored normal tuning.

Replace shorted c7110.Tuning System

CTC177 C7104 UHF poor. The VHF was normal. C7104 capacitor that goes to Q7101 was soldered

on

Tuning System




CTC177 Y7401 Tuner inop The tuning voltage was low. Checking the 4MHz

osci

Tuning System

ctc177af3 N\A Weak on all vhf stations. Found no voltages off

except agc high. Found through signal injection

that the signal was lost between cathode of cr7112

and cathode of cr7105. Traced to break under

c7137.

Jumped broken trace to repair set.f25250bcTuning System

ctc177cc c7319 No cable below ch 51. Band switch ok. Found

u7301 pin 9 at 1.5v and pin 11 at .4v. R7305 had

12v and 0v on it. C7319 was shorted to ground.

Removed the cap and the voltages and the tv

returned to normal operation.

Replace c7319.31gt657Tuning System

CTC177AC J3 No tuning. Voltages in pll circuit were normal, but

u7501 pins 7, 8 & 14 were at 30vdc on all

channels. U7501 pin 3 was at 12vdc, and didn't

change. Changed u7501 with the same result.

Resistance to ground from pins 8 & 14 we found

68k. Should have been 2

These resistors ground at j3 on the micro shield.

This tab connection was open. Repairing open

ground at j3 restored nor- voltages and tuning.


CTC177 Q7402 Tuner inop. The set had no high band VHF. The

low

Q7402 collector remained a negative voltage

while

Tuning System

CTC177 U7401 Tv would intermittently tune lower channels in

the same band while the ch. osd still showed the

orig.channel number. It would also stay tuned to

the same channel while trying to change channels

(ch. osd would indicate that channels were

changing). This w

Replacement of u7401 repaired tvG26683CK Tuning System

Ci it Ch i P t P bl S l tiM d l




CTC177ae C7313 Uhf good, vhf snow. U7301 pin 2 was down to

.6vdc. Lifting c7313 the voltage came back.

Replaced c7313.Tuning System

CTC177CD Q7404 Vhf ch. Were snowy. Found q7404 shorted. Replace q7404Tuning System

CTC177 R7514 Tuning inop channels 30 through 50 only. Measured 15V at U7501 pin 14, but 0.34V at

CR7108.

Tuning System

ctc177 cr7110 No vhf 7 to 13 or 22 up. Other channels ok.

Suspected band switching so we checked voltages

on the switching diodes. Anode of cr7110

measured 12 volts. It should have measured .8 if

diode was conducting. Diode checked open.

Replaced diode. Restored operation.Tuning System

CTC177 U7401 Pix flashes intermittently. Checking all the solder points around the tuner shTuning System

ctc177BD q7401 Will only receive channel 2 when the unit is

cold...after the unit is warm all channels work

fine. Putting cool spray on ic7401 will cause the

unit to fail. Found q7401 bad base would open

when cold.

Replace q7401G27681Tuning System

Ci it Ch i P t P bl S l tiM d l




CTC177 C7319 Tuning inop below channel 51. Band switch checked normal. Measured pin 9 of

U730

Tuning System

CTC177 J3 Tuning inop Voltages in PLL circuit were normal. U7501 pin

7,

Tuning System

CTC177 L2302 Tuning drifts. Channels 9 and 13 are slightly mist Replacing L2302 (off pin 62 of T-chip) repaired

th

Tuning System

CTC177 R7146 Vhf stations were snowy. Found zero volts on

q7102-g2 vhf rf amp.

Replaced open r7146.G25341Tuning System

CTC177 R7304 Tuner inop. The set will not tune VHF channels.

T h

There was no FLO signal at U7401 pin 11 with a

VHF

Tuning System

CTC177 Q7404 Very weak Snowy pix on channel 51 and up in the

ca

Q7404 had 11.9V on the emitter, 10.6V on the

base

Tuning System





CTC177 L2302 Chans 9 and 13 slightly mistuned and a slight buzz

in the audio in the background.

Replacing l2302 cured the problem.(off pin 62 of

t chip)


CTC177 U7401 With tv on channels 2 thru 6, 98 & 99 received a

detuned channel 18. All other channels were

snow. Tuning voltage (u7501-8) stayed at 27

volts.

Replaced u7401.GT506Tuning System

ctc177aa q7404 Very weak snowy pix on ch 51 and up in cable.

Looked at q7404 and found 11.9v e, 10.6v b, and

5v c when tuned to ch 53. Jumped q7404 e to c

and pix returned to normal.

Replace q7404.25gt506Tuning System

CTC177 WIRE Dead set int The white wire from E116 (near the tuner) to

E16 (

Tuning System

CTC177 C7506 Pix snowy on Hi-VHF and UHF channels. Low-

band VHF

U7301 and U7401 had been replaced. Checking

the vo

Tuning System

CTC177 J3 The set intermittently Changes channels and

Tuner

Repairing a bad solder connection at J3 (tuner shiTuning System





CTC177 Y7401 Vhf lo channels appear in uhf band. The tuning

voltage on the collector of q7401 was at +30

volts and would not change. Band switching logic

at u7401 pins 9 and 8 was working (indicating ic

was not dead). Checked oscillator on y7401 and

found it to be ve

Replaced y7401 and restored the oscillator

(typically around 1 vpp with a x10 probe) and

normal tuner operation.

25GT506Tuning System

CTC177 C7404 No tuning tuning voltage on the collector of

q7401 fixed at +30 volts. No oscillator voltage

pre sent on y 7401 . Th e gl ue u sed to f aste n c7 404

(off u7401 pin 2) had spread out and prevented

one side of the capacitor from being soldered.

Removed the excess glue and resoldered the c7404.25gt506Tuning System

CTC177 CR7303 Won't Tune channels 7 through 13. The collector of Q7402 switches from -14 volts

in

Tuning System

CTC177AE trace Snowy picture on vhf. Checking voltages found no

voltage to cr7111 & cr7113 (varactor diodes)

cathodes.

Repaired broken trace between r7511 and r7518.G26685WK Tuning System

CTC177AA R7129 All channels above 6 are snowy. Bandswitch

voltages, good. Voltages at u7501 pin 8 and the

cathode of cr7106, found u7501 had the correct

voltage but cr7106 had 0v on the cathode all the

time. Checking the circuit between u7501 and

cr7106, found one end

Resoldering r7129 restored normal tuning on all

channels.


ctc177 cr7303 Would not tune channels 7-13. The collector of

q7402 switches from -14 volts in low band, to +12

volts in high band. The voltage at the anode of

cr7303 also changed with the band switch, but the

cathode always had zero volts on it.

Replaced open cr7303.F25190seTuning System





CTC177 CR7303 No low vhf. Zero volts on both ends of cr7303. Replaced shorted cr7303.Tuning System

ctc177 r7408 Tuner tunes wrong channel. Ch2-6 gets ch18, 7-

13 gets 22. Found q7402 to be bad. It had 12ve

and 0vb+c in all bands. Repaced no change.

Q7401 c had the correct voltage On pin 3 of

u7501 was wrong On ch 2 had 1.8v on q7401

while had 6v on pin 3 of u7

Resoldering fixed the problem.g27341wk Tuning System

CTC177AE U7301 Some vhf channels were snowy.pin 1 on u7301

was low

Replaced u7301G26683Tuning System

ctc177aj2 c7144 No stations 7 and above. 2- 6 ok. Found the

collector of q7402 at 0v on c h 6 and 12v on ch 7.

Found c7144 shorted. Lifting cap returned

operation to normal.

Replaced c7144. j253 30blTuning System

CTC177 R7305 No vhf, uhf ok-vhf pll voltage was 30v on all

channels. Checking u7301-11 we found less than

1v.in the b+ line to pin 11 we found that 12v was

dropped across r7305 (620ohms). While solderingr7305, the tech noticed that the r esistor was

cracked. Subbing a

Replacement of r7305.Tuning System

ctc177 r7306 Nothing but snow. Q7402 had 12vc on ch 7 and

.7vc on ch 6. Q7401 had 9vc ch 6 and 0vc c h7.

Felt that q7401 probably wanted to go to 30v on

ch 6 so we followed the line going to cr7302 and

found that the voltage was dropping across each

resistor till we go

Cleaned under r7306 to repair set.Tuning System





ctc177ac trace No tuner. Found pin 8 of u7401 stayed low in all

band s. Q7 402 h as n o 12v .

Found open trace from fb4111 to 12v run c

source. Repair of trace fixed set.

f25190seTuning System

CTC177BG CR7305 Would not tune hi-vhf channels. Tthe collector of

q7401 in hi-vhf, had 33v (tuning voltage).The

vhf oscillator circuit at u7301 pins 9 & 11, there

was no evidence of the oscillator running.

Checking the varactors, cr7302 & cr7305 found

insufficient solde

Resoldering cr7305 restored normal hi-vhf tuning

operation.

G27665WK Tuning System

CTC177 R7151 Snowy picture on vhf channels. Checking voltages

we found no voltage to cr7108 (varactor) cathode.

Replaced open r7151.25GT506Tuning System

CTC177CC C7131 Poor cable tuning on channels 4 and above.

Channels 2- 6 useable, snowy picture on others.

Found a leaky c7131.

Replaced c7131.31GT657Tuning System

ctc177 c7102 Tunes only low vhf. Channels 7 and above are

snowy. Found that the dc voltage at the cathode

of cr7107 was low, 1.6vdc. Back at u7501-8

voltage was 3.6 volts. Lifting r7101 allowed thehigh vhf channels to come in good. Resoldering

r7101 and lifting c710

Replaced leaky c7102.G27687wk Tuning System

CTC177 U7501 Snowy picture. the voltages at u7501 were high

and not close to what they should be for various

channels

Replacement of u7501.Tuning System





CTC177 R7521 Audio weak. The set had only one weak channel. Q7501 (emitter) measured 21 volts instead of

1.06

Tuning System

CTC177 C7310 No tuning on any band, q7401-c at 0 volts.

Checking osc circuit, vhf tuning returne d by lifting

r7301. Checking cr7304-c, we found 9 volts, with

r7301 lifted should be 0 volts. Lifting c7310 still

gave 9 volts on cr7304-c. Removed glue from

under c7310 an

Remove glue from under c7310 in tuner.Tuning System

CTC177 C7116 Snowy picture there was a lost of g2 voltage on

q7102 transistor.

Had solder bridge under ca p c7116. C7116 goes to

ground from g2 of q7102.


CTC177 R7116 Uhf was ok but vhf was snowy on low and high

band s. Th e vo ltage on vh f rf . Amp . Q71 02 wa s g1

10 volts, g2 was 7 volts and source was at 7 volts.

The drain was ok at 11.5 volts.

Found resistor r7116 a 68k off g1 of q7102 was

open.

Tuning System

CTC177 R7146 Vhf was snowy uhf was ok. Had 1.3 v on q7102

g2. The agc voltage from u1001-12 had 7v all

the way to r7146. Had 1.3 on the other side of

r7146. Resistor checked good 47 ohm and noshorts to ground. Replacing resistor cured prob.

Perhaps we had leakage un

Replace r7146.F27351WNTuning System

CTC177 R7313 Low band (2-6) was fine but 7-13 was not there.

We found that cr7303 was not getting any voltage

in vfh high mode. Following back he saw that

r7313 had been cracked when someone removed

the tuner shield from bottom.

Replace open r7313Tuning System





CTC177 C7116 Pix snowy There was a lot of G2 voltage on Q7102

transistor.

Tuning System

CTC177 FB4110 The set had intermittent short Vertical/Streaks in The feed through bead FB4110, which supplies the

3

Tuning System

CTC177BF R7401 Upper channels in each band are snowy. The

lower channels in any band appear fairly normal.

With channel 6 selected, at u7501 pin 3 the

voltage was down to 1.1vdc. The collector voltage

at q7401 was 5.5v.

Found r7401, 191k 1%, had increase to 2.3meg

ohms. Temporarily installing a 220k resistor in its

place produc ed a norma l pict ure.


CTC177BE R7127 Wouldn't tune hi-vhf or uhf channels. Q7402

collector was switching between vhf-low & high.

On chan 13, checking the voltages at cr7109 and

cr7110, cr7109 was normal with .8v on the anode

and 0v on the cathode. Cr7110 anode near 10v

and the cathode 9v.

R7127 read open and a replacement restore solved

the problem.

F27351WNTuning System

CTC177CC R7304 Vhf both high and low were snowy uhf was okay

and u7301 had been replaced. Had proper band

switching and uhf and vhf switching was ok.

Voltages on u7301 measured ok except pin 11which was less than 1vdc.

R7304 a 1k smd was not solder on one end.31GT657Tuning System

CTC177CD R7306 Cable channels 2-48 tuned poorly, 48+ tuned ok

checking tuning voltages at varactor diodes, found

junc tion of c r73 02 & c r73 05 a t .09 vdc - ch eck ing

r7307 and r7306, tech noticed that the end of

r7306 connected to l7306 had never been soldered.

Soldering loose end of r7306 restored normal

tuner operation.





C cu t C ass s a t ob e So ut oode

CTC177 R7315 No tuning. We had 16v at q7401-c on channel 2.

Removing the collector we still had 16c on the

foil. Tracing out the foil we found a solder splash

from one side of r7315 to the ground stake at

g12. Set was a stock unit so splash must have been

from factory

Remove solder splash.G26661CK Tuning System

ctc177 glue Q7404+3 over heat and fail. Removed q7404+ 3, r7413, 14, and r7410,

cleaned board of glue and replaced components.

Tuning System

CTC177 CR7305 No vhf high band channels. The tuning voltages

on u7501 checked ok. The band switching

voltages were correct. The problem was isolated

down to the cathode of cr7305. When the probe

touched the cathode the vhf high band returned.

Resoldering the diode took

Resoldered cr7305Tuning System

CTC177 R7123 Tuner inop. The set had no VHF low or high band. R7123 (a 10 ohm SMD which goes to the (D) of

Q7102

Tuning System

CTC177BF R7114 Poor tuning on most channels; ch 2 was good,

higher ch's were progressively worse-agc voltage

was high on all channels. On ch 13, cr7106 in the

single tuned circuit had 5.7v on the cathode, butcr7107 in the same circuit had 0v on the cathode.

R7114 check

Replace r7114.F27671SETuning System

CTC177 C7102 Tuner inop. The tuner only tunes low VHF

channels.

The DC voltage at the cathode of CR7107 was

low at

Tuning System




CTC177 CBA Tuner inop Pin 8 of U7401 stayed low in all bands. Q7402

had

Tuning System

CTC177 R7121 Set had snowy vhf. Q7102 had 11 volts on the

source all the time. Found r7121 with a loose

connection.

Resolder r7121.Tuning System

CTC177 R7146 Tuner inop. The VHF stations were snowy. There was zero volts on Q7102-G2 (VHF RF

AMP). Rep

Tuning System

CTC177 FB4110 Set had intermittent short vert. And streaking in

pict ure and inte rmit tent snow y tun er.

The feed thru bead fb4110 supplies the 33 volts to

the tuner. Had bad solder connection on one end.


CTC177 U7301 Set had intermittent tuning bending the board

pictu re w ould come in. Wh en th e pic ture went

snowy the 12 volts disappeared from pin 8 of

u7301.

Found bad connection from 12 volt run to smd

r7312.


CTC177AK Y7401 Poor tuning. Unit was are serviced for bad

grounds around and under the tuner shield. Found

the leads on the xtal were never clipped and they

over extend the frame and touch the bottom

cover. Shorting out the xtal.

Clip the leads on the y7401 and reinstall the

cover.

25GC710Tuning System




CTC177AG R7401 Channels 7 and up tune but are snowy. Checking

voltages at u7501, we found on channel 7 that pin

3 was below 3vdc and should have been approx.

4v. At the collector of q7401 we read approx.

3.5v as called for.

Found r7401, 191k 1% resistor open.25GT536Tuning System

CTC177 Q3301 Autoprogramming would not operate. Traced the sync signal to the base of the sync ampTuning System

CTC177 R7119 No vhf but uhf was ok. Q7102 the vhf rf amp had

zero volts on the g2. Found r7119 open.

Replace R7119Tuning System

CTC177 L7306 UHF/VHF inop Resoldering L7306 (off pin 11 of U7401) repaired

t

Tuning System

CTC177 U7501 VHF/UHF inop The 33 volt supply to Q7401 and U7501-4

measured 5

Tuning System

CTC177 Q7102 Snowy vhf on lower and upper bands.uhf working

normal.

Replaced leaky rf amp q7102.Tuning System




CTC177 Q3301 No auto programming .Trace sync to base of

q3301 had no signal on collector.

Q3301 was open. Had 3 sets with this problem.Tuning System

CTC177 R7123 Had no vhf low or high band R7123 a 10 ohm smd which goes to the (d) of

q7102 the vhf rf amp. Was open.

Tuning System

CTC177AD L7306 No tuning vhf or uhf Resoldering l7306 (off pin 11 u7401) cured

prob lem.

G25341WK Tuning System

ctc177 trace No tuner. Found no voltage at pin 10 of u7401.

Q4106 had 12v c, -9v b, and 0v e. Broke the trace

between the b ase of q 4106 and r 4131 . The

negative voltage was on the resistors trace. Lifted

the resistor and the voltage went to a -11.5v. Put

the resistor

Ran a jumper from the floating end to the base of

q4106 and the set worked normal.

f27351wnTuning System

CTC177 C7411 Tuning incorrect. The set would not tune cable cha C7411 on the clock line of U7401-5 was

defective.

Tuning System

CTC177 C7118 Very weak tuner all channels. C7118 off of drain of q7102 shorted putting 12v

on

Tuning System




CTC177 C7144 Tuning inop above channel 6. The collector of Q7402 was at zero volts on

channe

Tuning System

CTC177 U7301 No uhf, vhf normal. u3201 had been changed

already. checking around pin 16, u7301 the pin

measured 1.3 volts instead of the 2.8 volts as

required.

Replacement of u7301 restored uhf operation.Tuning System

CTC177 R7305 VHF missing. UHF was normal. VHF PLL voltage

was 3

There was less than 1V on U7301 pin 11. R7305

was

Tuning System

CTC177 R7116 VHF snowy on low and high bands. UHF was

normal.

The voltage on the VHF RF amplifier (Q7102)

was 10

Tuning System

ctc177 q7402 Channel 2-5 ok, 6 weak, rest missing. On q7401

the tune volts were 1-2 volts higher than normal

on channels 2-6. Other channels had 31 volts.

Q7402 had 0 volts on its collector on allchannels. Found 0 ohms to ground on q7402

collector. R7142 had one end

Repaired by removal of short and replacement of

open q7402

25gt506Tuning System

CTC177 L7305 Set had no ch. 17. All other ch would come in.

Could see ch.17 but there was lines like it was

missed tune.

The servicer found spreading the winding of l7305

when the set was on 17 and the ch. came in good.

He then went back and check all the other ch. and

they were good.

F27351Tuning System




CTC177 SOLDER Vhf and ch. Up to 50 were ok. Ch. 51 and higher

was snow. The vhf/uhf switch transistors ( q7404

7403) collectors were at zero volts all the time.

Found a solder bridge from q7403 collector to

ground

Tuning System

CTC177 R7129 Tuner. Channels above 6 are snowy. No problems were found when checking

bandswi tch vo

Tuning System

CTC177 R7121 VHF snowy. UHF normal. Q7102 had 11 volts on the source all the time. FouTuning System

CTC177BF Trace No channel freq change. Any channel selected

would result in the correct osd, but only a drifting

ch. 3 would tune. Data & clock at u7401-4 and 5

were at 0v and 5v.found an open trace in the data

line between c7410 and r7405. Bridging the open

trace resto

Repair open trace from c7410 & r7405F27671SETuning System

CTC177 R7119 VHF missing. UHF was normal. Q7102 (the VHF RF amp) had zero volts on the

G2. R

Tuning System

CTC177 J3 Intermittently the channel changed and

intermittent no tuner signal (snow).

Corrected bad solder connection at j3 tuner shield

ground which grounds u7501-11.

F25190FETuning System




CTC177AC R7129 Channels 2-6 tune normally-higher channels are

weak. Checking voltages at tuning diodes, no

voltage was found at cr7106 & cr7107 in the

single tuned circuit. U7501-8 which feeds this

circuit had 5.6vdc. Checking the resistors in the

circuit found r7129 c

Replacement of r7129 restored normal tuner

operation

F25190Tuning System

CTC177AH R7310 No uhf- pll and u7501-7,8,14 voltages were less

than 1vdc in the uhf mode. Checking resistances

found a short to ground from cr7301 anode.

Removing r7310 from the circuit removed the

short. Replacing r7310 restored normal uhf tuning.

Replacing r7310 repaired set.25GT542Tuning System

CTC177 Q7402 No high band vhf, low vhf ok. Q7402 collector

remains a negative voltage while switching

between hi and lo vhf.

Replaced q7402 with open e-b junction.25GT506Tuning System

CTC177BE CR7302 No vhf but, uhf was ok. Tuning voltage on q7401-

c was 0 volts with vhf selected. Found one end of

cr7302 wasn't soldered.

Soldered one end of cr7302 (near u7301-11).F27351WNTuning System

CTC177 CR7109 Ch. 2-6 was okay and ch 51 up was okay. Ch7-

ch13 and up to ch. 50 was snowy. Found the

switching diode cr7109 with 5vdc on anode it

should have been .7 when foward bias.

Diode check good but when replaced it corrected

the problem.

Tuning System

CTC177 RF CONNE Pix snowy intermittently. Pushing on the cable lead would make the picture bTuning System




CTC177 R7129 Tuner is weak on channels higher than 6. Checking voltages at tuning diodes, no voltage wasTuning System

CTC177 C4117 Tuner inop Found no tuner voltage on Q7401. Traced the

probl e

Tuning System

ctc177 c7411 Cannot tune in cable channel 17. All other

channels normal. Found a bad c7411 on the clock

line of u7401-5. Dc to pin 5 was down to 4.1

volts.

Replaced leaky c7411.F27150swTuning System

CTC177 CR7305 VHF Hi band inop. Tuning voltages on U7501

were no

Isolated the problem to the cathode of CR7305.

Whe

Tuning System

CTC177 FB4110 Tuner int. Pix missing or Audio distorted when the The voltage on the collector of Q7401 dropped

to z

Tuning System

CTC177 C7401 Set had Snow and Video missing. After 15 to 20

min

During the failure, pin 6 of U7401 measured 1.4V,Tuning System




CTC177 U7301 UHF missing. VHF was normal. U3201 had been

replac

Checking around pin 16 of U7301 found 1.3V

instead

Tuning System

CTC177 Q7102 VHF snowy on lower and upper bands. UHF was

normal

Found Q7102 (RF amp) was leaky. Replacing

Q7102 re

Tuning System

CTC177 TRACE Channel change inoperative. Any channel selected

w

Data and clock at U7401 pins 4 and 5 were at 0V

an

Tuning System

ctc177 l7305 Ch 2- 6 and 14- 17 look ok. 18- 22 and 7- 13

weak. High agc voltage.

L7305 poor solder connection.f27631sf Tuning System

CTC177 Q7501 Tuning erratic. Midband cable was normal, low

VHF

The output at pins 7, 8 and 14 of U7501 were all bTuning System

CTC177 R7114 Tuning poor on most channels. Channel 2 was

normal

On channel 13, CR7106 in the single tuned circuitTuning System




CTC177CD C7323 No low vhf (ch's 2-6, 14-17)-q7401c stayed at

2.8v on low band -all voltages were normal on

band switch d iodes...d ue to t he lack of p ll

operation on low band, i suspected the oscillator

circuit.Tech solder connections on l7305 &

c7323. After soldering c73

Solder c7323.Tuning System

CTC177 Q7403, Q7 Q7403 fails/Q7404 fails Found a foreign substance around Q7403, Q7404,

R74

Tuning System

CTC177 L7601 Poor Tuning, Adjacent Channel Interference On

Chan

Replaced L7601.27GT617Tuning System

ctc177 r7304 No vhf below ch 51. Uhf ok. Found pin 11, 9 of

u7301 with no voltage. Found open trace on high

side of r7304 off of pin 11.

Repaired trace.f26631seTuning System

CTC177 R7315 Tuning inop There was 16V at Q7401 collector on channel 2.

Aft

Tuning System

CTC177 R7132 Tuning inop U7401 pin 5 clock line was at 2.6V. There was an

o

Tuning System




CTC177AF U7401 Intermittent dead or intermittent flashing in

picture. When the set was dead we found a bout 2. 5

volts on u3101 pins15 &16. But the voltage on

u7401 pins 4 & 5 was 5 volts.

Corrected bad solder connection on tuner shield

which grounds u7401-13.

F26251Tuning System

CTC177 U7301 VHF snowy on some channels. Pin 1 on U7301 was low. Found U7301 was

defective.

Tuning System

CTC177 SOLDER B UHF missing. VHF and channels up to channel 50

wer

The VHF/UHF switch transistors (Q7404 and

Q7403) c

Tuning System

ctc177 trace No tuner. Tap on board and pix would flash in for

a moment. No 12v to fb4111. Found broken trace

between pin 2 of d egauss relay and r4131.

Jumped break and set fixed.25gt542Tuning System

CTC177 R7310 UHF missing PLL and U7501 pins 7, 8 and 14 were less than

1VDC

Tuning System

CTC177 R7416 Set had no low vhf. High vhf was ok. Q7402 the

band s witch h ad been changed. Cololec tor of

q7402 had 11.5 positive in low and high vhf. In

low vhf it should be a negative 12 volts.

100k resistor r7416 between the base and emitter

had changed value.

Tuning System




CTC177 J7101 Pix snowy. All voltages were normal. Inserting RF Tracing all the way back to the RF connector, puttTuning System

CTC177 L7305 Tuning poor. Channels 2 through 6 and 14

through 1

There was high AGC voltage. Found a bad solder

con

Tuning System

ctc177 connector Snowy intermittent picture. Pushing in on cable

leadin would tend to make picture better.

Inspection of rf connector on tuner showed that

the center piece that the cable center conductor

mates with was pushed back so that it sometimes

would make contact

Using a small tool we moved the center pin and

insulator back into place and put a spot of rtv on

it. Corrected problem.

N\ATuning System

ctc177 c4117 No tuner. Found no tune volts on q7401. Traced

prob lem to c4 117. The cap was sold ered to the

tuner shield killing the 33v line. Problem was

caused by soldering the shields.

Resoldered c4117.f25251wnTuning System

ctc177ae j7101 Snow for a pix. Found all voltages ok. Inserted rf

from tag box into rf circuit and got a pix. Traced

all the way back to rf connector. Putting signal on

the lead coming out of j7101 we had a pix.Putting it in the connector we had none.

Replaced the rf connector j7101.g26681ck Tuning System

CTC177 C7145 Snowy tuning from channel 2-50. The diode

CR7108 v

Replace C714525GC731Tuning System




CTC177 R7304 VHF missing below channel 51. UHF was normal. Found pins 9 and 11 of U7301 had no voltage.

Found

Tuning System

CTC177CD R7132 No tuning: u7401-5 clock line was at 2.6v. Found

open trace at 21k in clock line. After repairing

trace tuning was weak. On ch.13, we found cr7108

cathode at 5.5v and anode a t 1.8v. R7132 in

cr7108 anode circuit measured 1.8k -should be 10

ohms- replaceme

Repair open trace at 21k & replace r7132.F31671SETuning System

CTC177 C7402 Poor tuning on channels in the upper portion of ea Replaced leaky c7402 off pin 1 of u7401.Tuning System

CTC177 L7111, L71 Pix snow intermittently. Checked all grounds. Found bad solder connectionsTuning System

CTC177 CR7302 VHF missing. UHF was normal. Tuning voltage on Q7401 collector was zero volts

w

Tuning System

CTC177 U7501 No vhf or uhf. 33 volt supply to q7401 and

u7501-4 measured 5 volts.

Replaced u7501 with pin 4 shorted.G25681WK Tuning System




CTC177AE C2307 Some channels had alot of jitter in them. Checked

the agc at pin 12 of u1001 and found it at 7.5

volts. At that time servicer noticed c2307 off pin

14 not soldered on one side. Resoldering c2307

repaired the set.

Resolder c2307.Tuning System

CTC177 L7304 Tuner inop. The tuner would not tune channel 50.

A

The coils at L7304 were too far apart. ReadjustingTuning System

CTC177 Q7402 Tuner will tune channels 2 through 5, channel 6 is Voltage on Q7401 measured 1 to 2 volts higher

than

Tuning System

CTC177 CR7305 Tuning inop for channels 7 through 13 and for

midb

There was a bad solder connetion on the anode of

C

Tuning System

CTC177 CR7305 Tuner would not tune Hi-VHF channels. Checking the collector of Q7401 in Hi-VHF

showed 3

Tuning System

CTC177 Y7401 Set had no tuning and the tuning voltage was low.

Checking the 4 mhz osc at u7401 tech found no

signal. Replacement of the xtal y7401 restored

osc and tuning.

Replace y7401F27671SETuning System




CTC177 C7104 Vhf was good uhf was snowy Found c7104 cap. Which goes to q7101 was solder

on one only.

G27683Tuning System

CTC177 C2307 Pix jitters The AGC at pin 12 of U1001 was at 7.5V. There

was

Tuning System

CTC177 R7511, R75 Pix snowy on VHF. Found no voltages on VR7111 and CR7113

(varactor d

Tuning System

CTC177 R7151 Pix snowy on VHF channels. Found no voltage to CR7108 (varactor) cathode.

R71

Tuning System

ctc177be r7411 Ch 2 ok but others get weaker as frequency

increases. Found that pin 3 of u7501 had 1.3v

when tuned to ch6. Lifting r7401 and r7525 we

only had .5v on r7408 instead of normal 1.1v.R7411 went up to 2.5 meg.

Replaced r7411 and set worked fine.27gt614Tuning System

CTC177BE L7304 Would not tune channel 50. All other channels

were ok.

Readjusting l7304 (we slightly made the coils

closer together) cured the problem

Tuning System




CTC177 CR7305 Will tune channels 2 ,5.will not tune 7-13, or

midband cable. Found anode of cr7305 not

soldered securely.

Resoldered anode of cr7305.Tuning System

CTC177 R7411 Tuner weak. Channel 2 was normal, but all others b Pin 3 of U7501 was at 1.3V when tuned to

channel 6

Tuning System

CTC177 CR7109 VHF snowy on channels 7 through 50. Channels 2

th r

Measured 5 volts on the anode of CR7109 - it

shoul

Tuning System

CTC177 U7301 Snow in tuner up to channel 45. The picture did not improve when a signal was injeTuning System

CTC177 U7301 Tuner inop. All channels would tune, but most had Pin 1 of U7301 was at 0.4V. It should have been

5V

Tuning System

CTC177 R7304 VHF snowy. UHF was normal. U7301 had been

replaced

Had proper band switching and UHF and VHF

switchin

Tuning System




CTC177 R4131 Tuner inop. The picture would flash for a moment

i

The 12V to FB4111 was missing. There was a

brok en

Tuning System

CTC177 R7307 VHF missing. The DC voltages on the cathodes of CR7305 and

CR73

Tuning System

CTC177BF C7410 Dead set, servicer had replaced u3201. Pin 5 of

u3201 was at 0 volts. Lifting jumpers jw408 and

407 restored the voltage to pin 5. Traced fault to

shorted c7410.

Replace c7410F27671SETuning System

CTC177 U7501 Pix snowy The voltages at U7501 were high and not close to

w

Tuning System

CTC177 C7131 Cable channels 4 and above would not Tune

prop erly

Found C7131 was leaky. Replacing C7131

repaired th

Tuning System

CTC177 TRACE Tuner inop Found no voltage at pin 10 of U7401. Q4106 had

12V

Tuning System




CTC177 R7146 VHF snowy. UHF was normal. Had 1.3V on Q7201 G2. Following the AGC

voltage fr

Tuning System

CTC177 R7313 Tuner inop on channels 7 through 13. Found that CR7303 was not getting any voltage in

V

Tuning System

CTC177AA R7307 No vhf tuning. The dc voltages on the cathodes of

cr7305, 7302 (vhf osc) were low when the set was

tuned from channels 2-13. Resistance

measurement of r7306 checked correct but when

r7307 was measured it checked close to 2 meg.

Replaced r730725GT506Tuning System

CTC177 R7408, Q7 Tuner inop. The tuner would tune the wrong

channel

Found Q7402 was open. It measured 12V on

emitter a

Tuning System

CTC177 CR7110 VHF missing on channels 7 through 13 and 22

upward

Suspected band switching problem. Checking

voltage

Tuning System

CTC177AA C7408 No tuning, u7401 pin 10 was at 0 volts. Q4106-e

was at 0 ohms to ground. Lifting l4104 removed

short. Traced fault to shorted c7408

Replace c7408Tuning System


hf hf i i h d l d d i d lfi



ctc177 r7408 Uhf snowy. Vhf missing. U7501 had 30- 33v on

pins 8, 14 , and 7. Pin 3 had 12v when q7401 had

10vc. Channel 40 uhf was used for these

measurements. Found r7408 to be open.

Replaced r7408 and pix returned to normal.f27351wnTuning System

CTC177BF C7604 No tuner signal and voltages in tuner were ok.

Checking voltages on q7601 we found 0 volts and

zero ohms on the base. Removing c7604 tech

found solder on board under the capacitor.

Remove shortF27671Tuning System

CTC177 C7604 Tuner inop. Tuner voltages were normal. Q7601 had zero volts with zero ohms on the base.

T

Tuning System

CTC177AA C7401 Set had snow with no video. After 15 to 20

minutes set would start working. Taking voltage

checks during the 15 minutes we found pin 6 of

u7401 measuring 1.4 volts should be zero.

Grounding pin 6 tuner was ok. C7401 was open

until it heated up.

Replacing cap. Fix the set.Tuning System

CTC177AG trace Snowy picture on some channels. Ch 2 was clear,

3- 6 snowy. Traced voltage to both sides of r7145

and found nothing on r7114. Jumping trace

repaired set.

Repaired open trace from r7145 to r711425GT536Tuning System

CTC177AA L7111 Set had intermittent snowy picture. All the

grounds had been done twice but set still had

intermittent snow.

Servicer found that there was bad solder

connections on the two coils l7111 and l7112.



CTC177 CR7109 T i i Ch l 2 th h 6 ld t Q7401 it hi f 12V t 0 3V CR7109T i S



CTC177 CR7109 Tuning inop. Channels 2 through 6 would tune,

but

Q7401 was switching from 12V to -0.3V. CR7109

was

Tuning System

CTC177 R7304 Won't tune vhf channels - uhf normal the initial

probl em wa s not rela ted t o a l oss o f vhf tunin g but

was intermittent in nature. The technician had

resoldered all the tabs tuner shield. Checking vhf,

found no flo signal at u7401 pin 11 with a vhf

channe

During the course of resoldering the ground tabs,

r7304 got wicked off from the circuit off u7301

pin 1 1. Re plac emen t re stor ed n orma l tu ner

operation.

Tuning System

CTC177 R7107 Tuner inop. Channel 2 was missing. As the

channels

Voltages checked normal. Connecting antenna to

pin

Tuning System

CTC177 C7506 Snowy picture on hi-vhf and uhf channels. Low-

band vhf w as norma l. U73 01 & u 7401 had b een

replaced. Voltages at u7501 were good. At q7102,

found normal voltages with an affected channel

selected. At cr7106 & cr7107 cathodes found 0v

when they should hav

Removing a hairline solder splash from c7506



CTC177 U7401 TV Locks up. The set turns on and then locks up.

A

Unsoldering jumper JW408 would cause all

functions

Tuning System

CTC177 WIRE The set was intermittent dead The white wire from e116 by the tuner to e16 by

the horiz is a ground connection. If either end as a

bad s older conn ectio n it w ill cause a int ermit tent.

Several reports on this ground con.



CTC177 R7416 VHF l b d i i VHF hi h b d Th ll t f Q7401 d 11 5V i b thT i S t



CTC177 R7416 VHF low band was missing. VHF high band was

normal

The collector of Q7401 measured 11.5V in both

low

Tuning System

CTC177 R7403 Tuner inoperative no change in dc bias to q7401-

c. Checking the pull up circuit for the collector

through r7403 and r7402 we found no problem

with resistance value or continuity of the traces.

Applying 30vdc through a 20k load to q7401-c

restored normal o

Resolde r7403. Servicer replaced the resistor for

good measure. Possible bad solder joint that

showed up under current only.

F25190Tuning System

CTC177 C7134 No low vhf tuning. High vhf ok. Checking the

collector of q7402 in low band mode we had -

2.3vdc. Lifting cap c7134 the voltage returned.

Change c7134 (off anode of cr7104Tuning System

CTC177 RN4501 Reduced Vertical deflection. The DC level at U4501 pin 1 was low, down to

9.34V

Vertical

CTC177 C4501 No vertical deflection. Horizontal line was about

a third of the way down from top of screen. 12v

run f measured 20 volts and voltage at cr4704

cathode measured 14v. Measured 5v at u1001-18.

Replaced leaky c4501 (u1001-18).F26631SEVertical

CTC177 R4519 Vertical would intermittently shift down from the R4519 was intermittently changing value.

Replacing

Vertical


CTC177 JC421 Vertical collapse and a line across the tube appro R4517 in the 12 volt run source was getting hot TVertical



CTC177 JC421 Vertical collapse and a line across the tube appro R4517 in the 12 volt run source was getting hot. TVertical

ctc177 r4517 Vertical pulled up from bottom 1.5 in. Servicer

had replaced cr4704 and r4702 for a dead set.

Found rn4501 pin 5 to be low. R4517 was open.

Replaced r4517 and vertical returned to normal.f25190seVertical

CTC177 C4501 The vertical will pull up from the bottom at times

or will stretch from center to bottom or may

appear to be breathing this way .pressing down on

c4501, c4503 will cause the vertical to react.have

seen several chassis fail this way.the sets may be

the ol

Replacement of c4501,c4503 (connected to pin

18, u1001).

F31631Vertical

CTC177 L2704 Vertical missing. U4501 (vertical output) and

RN45

The 7.6V source was missing on pin 7 of RN4501.

T h

Vertical

CTC177 TRACE Vertical missing. The 7.6V to the vertical circuit RN4501 was

missin

Vertical

CTC177 C4103 Dead set The secondary of the power supply (the 143 volt

es

Vertical


CTC177 C7131 Interference lines in picture including sparkles i Found capacitor c7131 open ReplacementVertical



CTC177 C7131 Interference lines in picture including sparkles i Found capacitor c7131 open. Replacement

repaired t

Vertical

ctc177 jc421 Vertical collapse and the line across the tube was

approx. 3-4" low. R4517 in the 12volt run source

was getting hot. Found the 7.6 volt source at pin

7 of rn4501 missing. This was throwing off the

inputs to u4501 and pulling down the output at

pin 5, p u

Found a loose connection at jc421 on the 7.6 volt

line. Repaired bad connection.

G27341Vertical

CTC177AG c4506 Neck of crt burned off apparent high current

through yoke windings c4506 vented

Replaced c4506 and u45o1F25651Vertical

CTC177 U1001 Vertical unstable intermittently. The set played f Monitoring the waveform during this failure revealVertical

ctc177aj2 u1001 Video rolls vertically but the osd is fine. U1001 defective25gh350Vertical

CTC177 C4501 The set had no Vertical deflection. A horizontal l The 12V run measured 20 volts and the voltage at

C

Vertical


CTC177 C4501 The set had no Vertical only a line appeared on t There was no ramp output signal from U1001 pinVertical



CTC177 C4501 The set had no Vertical, only a line appeared on t There was no ramp output signal from U1001 pin

17.

Vertical

CTC177 CR4501, U Vertical foldover. The top third of the picture wa CR4501 was leaky, but replacing CR4501 did not

fix

Vertical

CTC177 R4502 Insufficient Vertical sweep. R4502 (which is connected to one side of the

yoke

Vertical

CTC177 U1001 Intermittent ustable vertical. After extended burn

in he just happened to move the set in the right

way and saw the vertical centering bounce a little.

The raster geometry remained intact but the

centering bounced up and down 2 or 3 times and

then settled

Replaced u1001 and corrected the problem.Vertical

CTC177 CR4103 Excessive vertical size; 7.6v source @ u1001-32 re Replaced cr4103.Vertical

CTC177 TRACE No vertical had no 7.6 volts to vert circuit

rn4501. Had only 1.2 volts on the collector of

q4101 the 7.6 volt reg. The resistor r4106 had 12

volts on both ends.

Had open trace between r4106 and col. Of q4101.Vertical


ctc177 N\A Vertical drops intermittently just like a bad ground Secured c4505Vertical



ctc177 N\A Vertical drops intermittently just like a bad ground

connection. Have found several sets with a poor

connection on the negative lead of c4505.

Secured c4505Vertical

CTC177 trace Vertical stretched. Checking u4501 found pin 3 at

6 v. All other voltages were close. We found a

cracked trace from the resistor network rn4501

pin 6 to u4 501 p in 7. Repa irin g tra ce r esto red

operation.

Repair open trace from rn4501-6 to u4501-7Vertical

CTC177 R4517 Vertical foldover Checking the voltages at RN4501 in the vertical stVertical

CTC177 RN4501 Vertical not centered. Resistor network (RN4501) checked normal out

of ci

Vertical

ctc177 rn4501 Vertical not centered resistor network checked ok

out of ckt. Replaced and it fixed unit

Replace rn4501. Part#215499g26683Vertical

ctc177 u4501 Set comes on ok. As it warms up vertical begins to

stretch. Osd disappears and the unit buttons then

become inop era tive exce pt t he p ower butt on.

Signal to pin 25 of u3101 disappears. The vertical

ic had been replaced for another problem. This

probl em dev

Found tat u4501 was positioned a little higher

than where the holes line up. Putting the ic down

a bit on the heat sink so that it was more square

and the holes lined up corrected the problem.

Vertical


CTC177CC U4501.R45 Venetian blind effect across the screen in the form Replaced r4517, u4501.Vertical



CTC177CC U4501.R45 Venetian blind effect across the screen in the form

of narrow spaced horizontal lines.found r4517

open and a defective u4501. R4517 had helped

reduced the venetian blind effect.u4501 had

reduced the venetian blind effect completely.

Replaced r4517, u4501.Vertical

ctc177 r4519 Vertical would intermittently shift down from the

top 2-3 inches as if you were turning a vertical

centering control. Found r4519 intermittently

changing value. Had to try two resistors before he

found one that worked.

Replace r4519.F25190seVertical

CTC177 U1001 Vertical output ic runs hot. found low amplitude of

vertical signal coming out of u1001. replacement


Replacement of u1001.Vertical

CTC177 U1001 Video rolls vertically. The OSD is normal. Found U1001 was defective. Replacing U1001

repaire

Vertical

CTC177 N\A No vertical deflection and horizontal line was

above center.

Removed glue around c4501 & c4503 (u1001-18).F26251Vertical

CTC177 TRACE Vertical stretched. U4501 pin 3 was at 6V. All other voltages were

cor

Vertical


CTC177 rn4501 Reduced vertical deflection u4501 pin 1 dc level Replaced defective rn4501Vertical



p

was low, down to 9.34vdc feedback into rn4501

pin 4 was u p to 1 3.1vd c replaced de fect ive rn450 1

which was giving incorrect feedback to inverting

input of the vertical op amp.

pVertical

CTC177CC CR2702 Vertical sweep exhibits 3 pictures. Found cr2702

shorted, and c4501 and c4503 leaky

Replaced cr2702, c4501 and c4503.F31631SEVertical

CTC177 R4517 Vertical problems and/or snowy picture. Servicer

reports two sets with r4517 opening or partially

opening. The picture will go snowy with various

vertical problems from no vertical to intermittent

or bouncing vertical. R4517 will have 12v on one

side and

Replace r4517.Vertical

CTC177 trace Osd rolls, u3101 pin 25 has no waveform on it.

Pin 3 of u4501 has a waveform, but no waveform

was seen on jw309. Jumping the trace restored the

waveform to u3101 pin 25.

Repair bad trace from pin 3 or u4501 to jw309Vertical

CTC177AC CR4501 Poor vertical linearity- pulled up at bottom,

compressed in center and blank in top half except

for 4 separated lines. Found that cr4501 had

25.8v on anode and 8v on cathode. Replacementrestored normal vertical operation.

Replace cr4501.Vertical

CTC177 R4502 Insufficient vertical sweep. no improvement when

adjusting the parameters, value.found r4502

(connected to one side of the yoke circuit at

e4501) had increased in value.

Replaced r4502.Vertical


CTC177AG U1001 Picture would have 3 to 5 lines at a time running Replace u1001.Vertical



g

from bottom to top. Servicer noted he could see a

ripple in the vertical drive from pin 17 and could

make the ripple disappear by adjusting the

sharpness in the menu. Replacing u1001 repaired

the set.

pVe t ca

CTC177 U4501, R4 Horizontal Lines in pix. R4517 was open and U4501 was defective.

Replacing

Vertical

CTC177 C4501, C45 Vertical deflection missing. Horizontal line was a Found foreign substance around C4501 and C4503

(U1

Vertical

CTC177 RN4501 Intermittent Line pairing. Cleaning flux from around RN4501 restored

normal o

Vertical

CTC177 C4501 No vertical, line only. No ramp output signal

from u1001 pin 17 pin 18 had 5v on it. Lifting

pin 1 8 sti ll ha d 5v on th e pad. Re movi ng c4501

.1mf smd cap cleared voltage. Replacementrestored vertical sweep.

Replace leaky c4501F27150SEVertical

CTC177 TRACE OSD rolls U3101 pin 25 had no waveform. Pin 3 of U4501

has a

Vertical


ctc177 rn4501 Intermittent line pairing. Cleaned flux from Problem correctedf27631sf Vertical



around rn4501.

CTC177 SERV Set started out as dead set. Replacing the eprom

u3201 and it would come on but had no video.

Checking for video on pins 63 and 51 there was

no video. The servicer then changed u1001 with

the same problem.

Since the eprom had been changed I had the

servicer go into the service menu and check the

video level in second menu at p16. It was at zero.

As soon as he adjust the v value the video came

in. I had him adjust as stated in instruction.

Video

CTC177 C5002 Raster bright/Retrace lines The G1 voltage was 180VDC. After removing the

sock

Video

CTC177 U1001 Video smearing. The symptom looked like a bad

CRT.

The green output blanking pulse coming out of

U100

Video

CTC177 R2709 Pix pulling in slightly on the sides. The display Resistor R2709 was burned open. This resistor is iVideo

CTC177 R3311 OSD missing. The FSW signal was missing at pin 39 of U1001.

Th e

Video


CTC177 R2704 White areas are too white, the rest of the picture Found bad solder connection on R2704 (off theVideo



base

CTC177 Q5004 Bright screen with Retrace lines. The CRT had

been

The cathodes measured between 40VDC and

50VDC. Q50

Video

CTC177 Q5004 Video missing Checking CRT setup, the cathodes were all at

195VD

Video

CTC177 COPPER T Picture dark for the first 3 to 4 minutes of opera When the set is first turned on, pin 34 of U1001 iVideo

CTC177 U1001 Red missing There was no waveform out of U1001 pin 36.

U1001 w

Video

CTC177 R4303 Pix missing with a strong signal, Pix tears with a Had less than 1Vp-p at U11001 pin 25. Found

R4303

Video


CTC177 R2918 Set had no video. Had video into u2901 the d-pip Found the voltage on pin 43 was gone. R2918 aG27683Video



but no ne out . The chip had b een r eplaced. 1.5 ohm was open.

CTC177BH3 Lead Tech saw a shading on the left side of the picture.

This shade was difficult to see without the right

pict ure. Tech foun d the gree n lead to the k ine c ba

dressed near l4853 on the pincushion board.

Pulling the green lead away from coil the shading

disappea

Dressed green kine lead away from pincushion cba.F27250BCVideo

CTC177 TAB AT J3 Video missing/Audio missing. The video and audio

w

The shield that borders the microprocessor had a tVideo

CTC177 L2701 Had no green the base of q5002 was zero volts

but t here was 2 .6 vo lts a t the gree n out put o f

u1001.

Found open trace at coil l2701 which goes to

q5002.

Video

CTC177 TRACE Video missing/OSD missing When shorting Q5004 base to emitter, the video

and

Video

ctc177 c2704 On certain pictures set would show a green line in

the picture hi light area. Chassis movement

seemed to correct problem.

Found c2704 was not soldered in board.Video


CTC177 U1001 Video smear looks like a bad crt. The green output Replaced u1001Video



blanki ng pul se loo ked li ke saw tooth instea d of a

square wave. Coming out ot u1001

CTC177 U1001 No Closed caption operation. The signals on pins 24 and 25 of U3101 were

normal

Video

CTC177 R2704 Pix missing. OSD and audio were normal. There was video at pins 63 and 51 of U1001, but

no

Video

CTC177 C2704 Green horizontal bar on bottom half of picture

(changes). Intensity of green bar increases with

brigh tness of pic ture.

Installed missing c2704 (u1001-34).F31671SEVideo

CTC177 R2709 The pix was pulled in slightly on the sides. Other

than that the set worked fine except when you

brou ght u p the displ ay fo r the adju stmen t for

color. The little bar that should be present was not

there and if you increased the color you could not

decreas

Replacing r2709 repaired the set (resistor off pin

4 of flyback)

G25341WK Video

CTC177 U1001 No red. No wave form out out of u1001-36 Replaced u1001F31631Video


ctc177 u1001 Set would come on with high voltage, black Replaced u1001 and fixed the set.g27343hpVideo



screen, no audio, no osd, and could not be turned

back o ff. Cou ld see chang e in da ta on data l ines

when buttons were pushed.

CTC177 U1001 Pix missing/Audio missing/OSD missing. The set

wou

Could see change in data on data lines when buttonVideo

CTC177 L2701 Green missing The base of Q5002 was zero volts, but there was 2.Video

ctc177e trace No video. No osd. Shorted q5004 base to emitter

and video + osd reappeared. Customer settings ok.

Looked at voltages on u1001 and found pin 31 at

0v. Traced problem to an open trace between

r2732 and jw318 off of pin 4 of the fly. R2732

had 7.6v on both s

Repaired trace and set worked normal.20gt375Video

CTC177 R2918 Video missing Video was present into U2901 (the D-PIP), but

ther

Video

CTC177 None Black screen intermittently. Removing the tuner shield on the bottom of the

cha

Video


ctc177 trace Dark picture for first 3-4 minutes then no control

Wh h i fi d i

Found an open ckt at 6-g on the chassis, between

h i

f25190seVideo



over contrast. When the set is first turned on, pin

34 of u1001 is at 5 volts and slowly goes down to

2.8. Pin 35 starts at 0 volts and slowly goes to

2.8. Pin 31 also starts low a nd builds to 5vdc.

Found

these two points.

ctc177BE r2704 White areas in picture are too white but the rest

of the pic is ok.

Resoldered r2704 off the base of q2704 the video

buffer

Video

CTC177AD U1001 No picture or osd and sound ok. Found video at

u1001 pins 44 & 48. Beam sense voltage at

u1001-31 measured 2.8 volts. Traced low voltage

to a 550 ohm leakage on u1001-16 to ground.

Note :u1 001 pins 16 & 31 a re c onne cted to get her

via r2731 & r4523.

Replaced u1001.G25341WK Video

CTC177AG R2704 No picture, normal osd and audio. Checking

u1001, video at pins 63 & 51 but no luminance at

pin 4 8. At q270 4, th ere was no vi deo o n the base

or emitter. Voltages read 0v on all leads of the

transistor. Resistance to ground from the base read

a short. Lift

Removing and reinstalling r2704 (1k base to

ground) removed the short and restored normal

pictu re.

25GT536Video

CTC177 C2704 Green Horizontal bar on the bottom half of the pic Replacing C2704 (U1001-34) repaired the set.Video

ctc177 short No closed caption. Signals on pin 24 and 25 of

u3101 ok. Had video on pin 13. The signal was

only .2v p-p. Went to u1001 pin 44 to check

waveform but noticed pin 44 was soldered to pin

43.

Removal of solder bridge repaired set.27gt617Video


CTC177 JC416 Video missing. There was video out at pin 51 of

U1

Jumper JC416 (that feeds video back to pin 48)

h d

Video



U1 had

CTC177 C2704 On certain pictures the set would display a Green Chassis movement seemed to correct the problem.

C2

Video

CTC177 C2701 Set had a slow vertical roll. Had tech scope pin 48

of u1001. The waveform was at .8 volts p/p.

Traced back to c2701, one side was at 1.2 volts

p/p. Repl ace c270 1 an d pic ture retu rned to no rmal .

Replace c2701 in video circuit.Video

CTC177 U1001 Pix missing/OSD missing. Audio was normal. Had video at U1001 pins 44 and 48. Beam sense

volt

Video

CTC177 JC416 Had video out pin 51 of u1001 and had video in

and out of pip ic u2901. But had no video at pin

48 of ic 1001.

Found jumper jc416 that feeds video back to pin

48 not solder on one end.

Video


Safety information is contained in the appropriate Thomson Inc. Service Data.

All product safe ty requirements must be compl ied with prio r to returning the instrument to



All product safe ty requirements must be compl ied with prio r to returning the instrument to

the consumer. Servicers who defeat safety features or fail to perform safety checks

may be liable for any resulting damages and may expose themselves and others to

possible injury.

©2003 T homs on In c. A ll Rights Reserved

www.thomsonservice.com

8/4/2003

CTC-177 Guia de Fallas

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