[TechAssist] Re: RCA F36673 intermittent shut down and power up
- From: "Robert McPherson" <rm502@xxxxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Wed, 15 Mar 2006 09:10:00 -0500
Barry:
Here's a collection of some CTC187 Tips. Hope this helps!
RCA Chassis CTC187
RCA Chassis CTC187BD2 Model F27672ET 27" TM TV Dead Tuner shield grounds?
The ground around the tuner can also cause eeprom and microprocssor failure.
If HZ output transistor is shorted, check C4407 ( .047 uf RCA # 214754 ) for
open.
CTC187 SHUTS OFF INTERMITTENTLY CHECK/REPLACE ON FLYBACK PINS, ESPECIALLY
1,2,8,10
CTC187 WILL NOT TUNE ANY CHANNELS - ONLY HAS SNOW CHECK/REPLACE Y7401 (P/N#
182839)
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)
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)
CTC187 PICTURE BOWED ON THE SIDES AND NARROW WIDTH DURING CHANNEL CHANGE
CHECK/REPLACE C4407 (P/N# 214754)
CTC187 MISSING ONE OF THE PRIMARY COLOR - RED,BLUE OR GREEN CHECK/REPLACE
IC1001 (P/N# 215524)
CTC187 DEAD SET WITH HIGH PITCHES SQUEAL CHECK/REPLACE Q4401 (P/N# 217654 OR
2SD1555) AND CR4402 (P/N# 198596 OR ECG5808)
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
CTC187 INTERMITTENT TUNER OPERATION CHECK/REPLACE Y7401 (P/N# 182839)
CTC187 SET SHUTS OFF INTERMITTENTLY CHECK/RESOLDER CONNECTIONS ON FLYBACK
XFRM. - ESPECIALLY PINS 1,2 & 3
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
CTC187 REGULATOR IC FAILS WHEN REPLACED - POWER SUPPLY SQUEALS AS THOUGH
THERE IS A SHORT ON SECONDARY CHECK/REPLACE C4137 (680pF @ 500v) FOR LEAKAGE
CTC187 INTERMITTENT LOSS OF AUDIO OR VIDEO CHECK/RESOLDER CONNECTIONS ON ALL
GROUND SHIELDS AROUND TUNER AND SYSCON IC
CTC187 MENUS ROLL VERTICALLY ON SCREEN -- VERTICAL RETRACE ON THE TOP 3-4
INCHES OF SCREEN CHECK/REPLACE IC4501 (TDA8172)
CTC187 PICTURE GOES BLACK AFTER A 1/2 HOUR - OSD/AUDIO IS NORMAL
CHECK/REPLACE U2903 (7805 REGULATOR)
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)
ctc187cl3 Problem:intermittently would not tune cable channels below 51
Solution:L7109 in tuner was intermittently open. 3.9uh pn 200559
RCA Model: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)
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 (Sears) CTC187CK Vertical is rolling (menu does not roll) Repalced
IC1001, T-chip (LA7610)
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.
CTC 187BD2 Sides bowed in. Pincushion problem. CR4403 and C4407
GE 27GT618 CTC187BD2 Dead CR4106 (140V supply to HOT) part#
164589/PFR856 R4110 (R110U, 33K ohm1W) C4107(100 mfd@250VIC U4101
(STK730-010)) 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
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 THINK THIS APPLYS TO ANY RCA / GE CHASSIS WITH TUNER
ON BOARD
Chassis:ctc187 Narrow on sides, width and height vary with scene change
Replace c4407 and cr4403. (will test good)
GE Model:31GT660 CTC187CH6 No Start Up, Fuse OK. Main Cap. Shorted. C4007
200 volt X 680Mfd.
Comments:Also CR4002 just off C4007 leg needed resoldering.
RCA Model:F31672ET Chassis:CTC187CL2 Dead- power supply squeels H.O.T.
Q4401 = BUH517 + bad connection L401 (cause of HOT failure)
RCA Model:F32672SB Chassis:CTC187CL3 Rattling and arcing noise when power
is pressed. Resolder FB402 and CR4403 at location T-11
RCA Model: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
QUESTION No. P1125-1: RCA model CTC187 in for repair that has an hourglass
effect. Looks like a pincushion problem. Picture and sound are perfect other
than being bowed in on both sides an equal amount.You have a bad filter cap
in you power supply which is passing Ac.It usually is the largest capacitor
in the set mounted toward the front.2nd answer: Possibly the pincusion
problem is caused by a faulty cap and diode, they are a blue rectangular cap
and the diode is in front of it.Sorry I do not have the values or locations
for you but they are veryclose to the heat sink near the center of the
board. The blue cap willbulge a bit if you look closely.
Robert McPherson
Computer & Television Service
1322 Durrett Lane Louisville, KY 40213
Telephone (502) 367-9324 Cellphone (502) 298-6997
Email rm502@xxxxxxxxxxxxx
----- Original Message -----
From: "Barry" <foxhole@xxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Wednesday, March 15, 2006 8:53 AM
Subject: [TechAssist] RCA F36673 intermittent shut down and power up
This CTC187CL3 will be running fine on the bench and shut down, if left
plugged in it will come back on an hour or two later and play for a half
hour and shut down again.
I have resoldered the tuner wrap and the flyback, has anyone any tips?
Thank You,
Barry MacInnes
Television Service Clinic
2 Church St. W.
W. Lebanon,NH 03784
foxhole@xxxxxxxxx
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