I have a GE 35GT690 chassis # CTC187CN3 that is dead. The standby supply doesn't even work. When I received the set the main fuse was blown. Upon further investigation I quickly found U4101, the main regulator was shorted. After replacing it, the set still didn't work. I then found CR4106 the main 140V source rectifier was shorted. After replacing that, the standby power supply still doesn't start up. There don't appear to be any obvious shorts on any of the loads. It appears to me that U4101 won't start up for some reason.
Pins 4,5 and 6 of U4101 each measure about 23.5V and 11 and 12 160V. Everything else measures 0V. Pin 1 the input, measures 0V. So whatever starts up U4101 is missing.
I also checked C4127, C4407, C4402, CR4402, CR4403 and R4305. All appear to be ok. At least they are not open or shorted. Leaky, I'm not sure.
Anyone familiar with this chassis and has any helpful hints or suggestions please respond.
Thanks.
Here are some of my old notes on the old CTC 187 chassis Good Luck Hope these help you. .
RCA
N/A
CTC187
SHUTS OFF INTERMITTENTLY
CHECK/REPLACE ON FLYBACK PINS, ESPECIALLY 1,2,8,10
RCA
N/A
CTC187
WILL NOT TUNE ANY CHANNELS - ONLY HAS SNOW
CHECK/REPLACE Y7401 (P/N# 182839)
RCA
N/A
CTC187
SET DISPLAYS 'UNUSEABLE SIGNAL' ON CERTAIN SCENE CHANGES WHEN USING THE S-VIDEO OR INPUT JACKS
CHECK/REPLACE C1401 AND C1402 TO (1uF) (P/N# 220998)
RCA
N/A
CTC187
AGC OVERLOAD - PIN #12 OF U1001 STAYS AT 8 VOLTS - WHEN 'IF' IS INJECTED AT PIN #1 OF U7301 , THEN NORMAL PICTURE
CHECK/REPLACE U7301 (P/N# 215532)
RCA
N/A
CTC187
PICTURE BOWED ON THE SIDES AND NARROW WIDTH DURING CHANNEL CHANGE
CHECK/REPLACE C4407 (P/N# 214754)
RCA
N/A
CTC187
MISSING ONE OF THE PRIMARY COLOR - RED,BLUE OR GREEN
CHECK/REPLACE IC1001 (P/N# 215524)
RCA
N/A
CTC187
DEAD SET WITH HIGH PITCHES SQUEAL
CHECK/REPLACE Q4401 (P/N# 217654 OR 2SD1555) AND CR4402 (P/N# 198596 OR ECG5808)
RCA
N/A
CTC187
AUDIO DROPS OUT WHILE IN THE SAP MODE
REMOVE C1609 AND REPLACE WITH 47uF @ 25v (P/N# 193043), ADD A 100k (P/N# 192084) ACROSS C1609
RCA
N/A
CTC187
INTERMITTENT TUNER OPERATION
CHECK/REPLACE Y7401 (P/N# 182839)
RCA
N/A
CTC187
SET SHUTS OFF INTERMITTENTLY
CHECK/RESOLDER CONNECTIONS ON FLYBACK XFRM. - ESPECIALLY PINS 1,2 & 3
RCA
N/A
CTC187
SET HAS AN ARC OF VERY FINE LINES IN THE TOP 1/3 OF PICTURE
CHANGE R4868 WITH A 2.2 2 watt RESISTOR (P/N# 215211) DRESS ALL WIRES AWAY FROM L4853, L4001 AND T4101
RCA
N/A
CTC187
REGULATOR IC FAILS WHEN REPLACED - POWER SUPPLY SQUEALS AS THOUGH THERE IS A SHORT ON SECONDARY
CHECK/REPLACE C4137 (680pF @ 500v) FOR LEAKAGE
RCA
N/A
CTC187
INTERMITTENT LOSS OF AUDIO OR VIDEO
CHECK/RESOLDER CONNECTIONS ON ALL GROUND SHIELDS AROUND TUNER AND SYSCON IC
RCA
N/A
CTC187
MENUS ROLL VERTICALLY ON SCREEN -- VERTICAL RETRACE ON THE TOP 3-4 INCHES OF SCREEN
CHECK/REPLACE IC4501 (TDA8172)
RCA
N/A
CTC187
PICTURE GOES BLACK AFTER A 1/2 HOUR - OSD/AUDIO IS NORMAL
CHECK/REPLACE U2903 (7805 REGULATOR)
RCA
N/A
CTC187
NO HORZ. SWEEP - ONLY HAS ONE VERTICAL LINE
CHECK/REPLACE C4403 (PART NUMBER VARIES DEPENDING ON CRT)
RCA
F31672
CTC187
MISSING ONE OF THE PRIMARY COLOR - RED,BLUE OR GREEN
CHECK/REPLACE IC1001 (P/N# 215524)
RCA
F32632
CTC187
AGC OVERLOAD - PIN #12 OF U1001 STAYS AT 8 VOLTS - WHEN 'IF' IS INJECTED AT PIN #1 OF U7301 , THEN NORMAL PICTURE
CHECK/REPLACE U7301 (P/N# 215532)
RCA
F35670
CTC187
AGC OVERLOAD - PIN #12 OF U1001 STAYS AT 8 VOLTS - WHEN 'IF' IS INJECTED AT PIN #1 OF U7301 , THEN NORMAL PICTURE
CHECK/REPLACE U7301 (P/N# 215532)
RCA
F27672
CTC187
PICTURE BOWED ON THE SIDES AND NARROW WIDTH DURING CHANNEL CHANGE
CHECK/REPLACE C4407 (P/N# 214754)
RCA
Chassis:ctc187cl3
Problem:intermittently would not tune cable channels below 51
Solution:L7109 in tuner was intermittently open. 3.9uh pn 200559
RCA
F27641BC
Chassis:CTC187AB
Problem:No pic. No snd. No brightness. HV OK.
Solution: CR4704 (207878 Diode Kit); R4702 (3.3 ohm 2w); R4517 (24 ohm 1w)
Comments:Could hear high voltage come up at turn on. R4702 & R4517 burned open. CR4704 shorted. Must use RCA 207878 special high temp diode. NTE sub will not stay!
RCA
Chassis:RCA (Sears) CTC187CK
Vertical is rolling (menu does not roll)
Repalced IC1001, T-chip (LA7610)
Comments:Even though the vertical sync signal at pin 17 of U1001 was correct amplitude and frequency (according to Sams), a new IC repaired the problem.
RCA
CTC 187BD2
Sides bowed in. Pincushion problem.
CR4403 and C4407 fixed the bow.
GE
27GT618
CTC187BD2
Dead
CR4106 (140V supply to HOT) part# 164589/PFR856 R4110 (R110U, 33K ohm1W) C4107(100 mfd@250VIC U4101 (STK730-010))
Comments:Main v. regulator IC U4101 (STK730-010) should have a negative 40 volts at pin 1 (pin 3 hot ground as reference) if working. Zero volts. Bad U4101. Final fix,replace U4101
RCA
ctc187ck
This set would very very breifly pulse up on HOT collector at plug in, and B+ was on collector, thereafter there was no activity evident from micro or anywhere when pwr button was pressed.
U3201 part #223954 was bad.
RCA
PS27108
CTC187BF2
NO VHF CHANNELS LOW OR HIGH BAND UHF CHANNELS OK
REPLACED U7301 215532
Comments:THINK THIS APPLYS TO ANY RCA / GE CHASSIS WITH TUNER ON BOARD
RCA
Chassis:ctc187
Narrow on sides, width and height vary with scene change
Replace c4407 and cr4403. (will test good)
GE
31GT660
CTC187CH6
No Start Up, Fuse OK.
Main Cap. Shorted. C4007 200 volt X 680Mfd.
Also CR4002 just off C4007 leg needed resoldering.
RCA
F31672ET
Chassis:CTC187CL2
Dead- power supply squeels
H.O.T. Q4401 = BUH517 + bad connection L401 (cause of HOT failure)
RCA
Chassis:ctc187
eeprom replacment
build a double eeprom socket
Comments:To shorten eeprom replacement time, build an eeprom fixture. You need 2ea 8-pin sockets, 1 dpdt switch, 1 small bread board, 4-pin header, and some wire. Conect it so that the switch switches the clock and data lines(pins 5&6).Pin 8 is +5 and gnd pins1,2,3,4,&7. How this helps is if you have a bad eeprom install old and new eeproms in sockets conect in place of eeprom on chassis, start set with new eeprom, swith to old eeprom and look to see if tuner data is salvagable and wright it down, switch to new eeprom adjust values, turn set off and install new eeprom on chassis.
RCA
F32672SB
Chassis:CTC187CL3
Rattling and arcing noise when power is pressed.
Resolder FB402 and CR4403 at location T-11
RCA
F31672ET
CTC187CL2
00 Would not select "VIDEO" input
EPROM RCA# 223957
RCA
F31672ET
CTC187CL2
DEAD, REPLACED HOT AND REPAIRED HOT DR TRANS, THEN HOT RAN VERY HOT
REPLACED Q4401 [USED OEM] CR4402, C4403, R4126, R4868
Comments:Q4401 223942 CR4402 242907 C4403 214753 R4126 215206 R4868 217315 BE SURE TO CHECK SOLDER AT HORIZ DR TRANS T4301
Found a bad U4101 and shorted CR4106. Also replaced C4105 and C4127 for good measure.
Thanks.
Glad you fixed it! Thanks for reporting back to us. I have lots of RCA or GE notes if you need more assistance.
ctc187 set was dead found reg ic shorted horiz out trans shorted also 140 b+ diode shorted replaced all parts cut the set on played about 30 sec then shorted the same parts out again also rang the flyback it checked good
anyone have any suggestions
Bump... if there is such a thing.
Working on a ctc187 myself, a big-fat console boob-tube TV from 1992. Found the service manual easily enough ( http://www.eserviceinfo.com/download.php?fileid=31439 ). But I got lost in it, a bit. Dead set after unplugging it for about 10 hours. Previously worked like a dream, perfect picture, excellent sound (although the R-channel audio would sometimes go out until cycling power off/on).
I found that the pin 16 (smps controller VCC) voltage was sine-waving on me around 6-7 VDC, testing out my shiny new digital oscilloscope. When I unplugged the set, I saw what was going on: voltage would climb to about 7 volts, the IC seems to have switched on, and the voltage drops until it switches off again. The recharge slowed down as the capacitor drained over about 30 seconds but the discharge always lasted the same length.
My first thought was R4003, a 2w/33k resistor that provides power to the regulator logic from raw B+ (which shows 160v on mine). It tested (on the board) way out of range, so I thought it was to blame (I since learned to stop testing components on-board). I took it out and it tested 33K. Damn. Fiddling around a little more, I've made little to no more progress on it. I replaced the 33k resistor anyway. Still no good.
I'm getting lost on this one. There are no blown parts I could find. But I've got to get it working... =(
edit: FWIW, pin 16 is the controller VCC connection and should be ~12 volts. Nothing on that IC should reach 160 volts - I'd suspect that the parts later down the schematic are open circuit (check R4126 in particular, it seems to like getting hot - it's a blue/teal resistor, 8.8 ohm, 3W, near the controller's pin 1/16 side). Or R4149 (1.2 ohm, 1w). If it's getting a high voltage, it'll shut down.
See, if I had a definitive symptom like that, this service manual would be helpful! ;)
edit edit: Huh?? None of those voltages make sense... pins 4, 5, 12, and 13 are ground pins (linked together no less), pins 1, 2, 6, 7, 8, 9, 10, 11, and 14 are signals/controls; only 15 and 16 are voltage pins. Pin 1 is marked on the copper side of the PCB; or from the top, the left pin on the side with the notch. The numbering wraps around the IC, so it's numbered downward from that corner, then wraps around the bottom, and back up to the top with the notch as pin 16. Careful about that numbering! ;)
i know those sets can be real dogs to repair and the only common parts to go bad in those are the regulator with a few small parts connected to it.
Larry
HELLO CHASIS CTC187CL2 OF A RCA, AND WHEN I turn on the power on the tv it burn the fuse.if you can give a sugestion i will be gratefull thanks.