[TechAssist] Re: Dead CtC197

Warren: Here's some tips I've collected over time for the 197 chassis.
Sorry I haven't had time to edit them yet.  Hope this helps.

RCA Chassis CTC197


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RCA 36" Model F36676ET(FM1) Chassis # CTC197CD DOP 5/97 Bloomington


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COMMON FAILURE PARTS

C14122 .033uf J 400v Gray Rectangular Polystyrene RCA # 214747

C14128 100pf K ZPP 500v (Ceramic Disc?) RCA # 120832

CR14112 RCA # 214653

CR14122?

IHVT RCA # 237506

Q401 EB 0 ohms

R14126 30Kohms @ 2 watts RCA # 238295 @ 3 watts RCA # 215206

Regulator Transistor RCA # 237469 (NTE 2397)


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CTC197CE2 et tries to come on 3 times, if unsolder collector of horizontal
o/p chassis will run. A: Dead, pulsates three times, unsoldering collector
of horizontal output transistor found that set would start (power supply was
OK). If set starts replace IHVT (flyback). Common on this chassis

Proscan Model # PS36125 Chassis # CTC197CG Q: HZ Output Transistor Failure
A: Unsolder, scrape leads, and resolder coil between HZ Driver Transformer
and Base of HZ Output Transistor

RCA Chassis # CTC197CG Q: HZ Output Transistor Failure A: Unsolder, scrape
leads, and resolder coil between HZ Driver Transformer and Base of HZ Output
Transistor

PROSCAN CTC197AD3 HSPF# 4176 RCA CTC197AC HSPF# 4113 RCA CTC197AH HSPF# 4229
RCA CTC197AH2 HSPF# 4196 RCA CTC197AH3 HSPF# 4296 RCA CTC197AK2 HSPF# 4066

RCA CTC197CA HSPF# 4052 RCA CTC197CJ3 HSPF# 4389RCA CTC197CK HSPF# 4389

RCA PS27600 CTC197All snow Unit has no tuning of any channel from the main
tuner. When monitoring the tuning voltages at U17501(5,6,7,& 8) were all
running at 30 volts no matter what channel the TV was on. Inspecting all the
tuning voltage paths from the PLL chip U17501 found that the path that Pin 5
supplied had a 52K resistance to ground. On the other side of R17508, a 47K
resistor we found the resistance path to ground was 4.2K. Capacitor C17713
was leaky. PN# 192020.


PS32109 CTC197Arcing Serial # 738560420J Unit will not turn on but there is
an arcing in the neck of the tube. Unit has a defective CRT. CRT #
A80AEJ16X09 VLS # TG9194-AF

Proscan PS36500 CTC197Arcing (Snivits) 36 " ctc197 that has a weird symptom.
First of all, its intermittent. second its not affected by freeze or heat.
symptom is picture starts to get horizontal tearing and break up
and 1" vertical band of snow band on the left side. It will get worse and
eventually take over picture and the flyback and yoke starts making a
sizzling type noise and then all of a sudden it just stops. Also does it
in aux input mode. The interference was picked up not only by other tvs in
the shop but also by radios. NOTE: I started working on this in customers
home and found that the ground pin for the focus/screen controls was
completely open, I soldered it back but at the time didn't give it allot
237506 flyback was cause. I just bet
this was the cause of this rare problem


RCA F36690 CTC197 Auto program Takes too long to change channels Will not
autoprogram. But it will manually program and store all the channels in the
memory.Tech needs to initialize the EPROM with the chipper checker and
create a file for the product. It may require the alignment of the IF VCO or
IF APC. Each one will cause the set to be sluggish and Cause the set to not
auto program 100% of the time.

RCA PS27500 CTC197AUTO PROGRAM Tuner skips several channels when using the
auto program feature.Unit had a broken trace at C509

RCA PS36700 CTC197AUTO PROGRAM Unit has two symptoms. 1. If the channels are
direct accessed the set will take 15 seconds to before the picture would
show up. 2. When the volume, brightness, contrast, etc. is adjusted the set
will take too long for the execution of the function. The bar graph will
take 1o to 15 seconds to execute the next level up. The T4 chip VCO is not
running at the correct frequency. When measuring the U16201(12) we found the
voltage too high (7+ volts)`. When the set is placed on a active channel,
and the voltage is checked on this pin it was over 6.8 volts. Using the
chipper checker we were not able to reduce this voltage lower than 4.9
volts. It must be 3.8 volts + or - 0.8 volts. It is suggested the VCO coil
be replaced (L12302) part number 215502

RCA PS36700 CTC197 BAR ON SCREEN Unit operates fine intermittently but the
lower portion of the screen has a 50 IRE bar that matched exactly the size
of the PIP box. When the PIP box is invoked and
moved up the screen the 50 IRE bar moves with it.Because of the thorough
description of this symptom it appears the trouble must be in the FPIP IC
U18100. This IC is used for the PIP and comb filter for both main and pip
video.

PS36605 CTC197 BLUE SCREEN Unit has a blue screen. Cannot achieve cut-off
with G2. When tapping on the neck of the tube the blue screen returns to
normal but will turn blue again in a few seconds.Tech will need a
replacement CRT A90AEJ16X09. CRT approved by TCE tech line.

RCAF36680CTC197CHANNEL CHANGE INOPERATIVEF36680 serial 831331772X Unit will
not change channels. The display changes but the internal tuner will not.
Seems to be stuck on channel 9.Tech needs to deselect all entries in the TV
guide plus menu relating to the questions; Do you have a CATV BOX? Do you
have a VCR? Do you have DSS?. Select "NO" to these items. It will give the
tuner control functions back. If any of the items are selected "YES" then
the customer will need a device that came with the set called a
IR Blaster. It plugs into the rear of the set in the "G-LINK" connector. It
enables the TV to "Talk" the VCR or CATV box Through the IR G-LINK. It will
control them if the user wants to have the TV Guide plus put the VCR
into record (timer type recording) or when the TV downloads the TV Guide
plus data, It must search for a Host Television station that transmits the
TV-GUIDE PLUS data. The TV change the channels on the CATV BOX rather than
the TV if the only input to the set is a CATV BOX.

PS36700 CTC197 CHANNEL CHANGE INOPERATIVE Unit has no tuning of VHF channel
even though the channel display is changing. Checking the band switching at
Q17503 Q17504, & Q17505 finds that everything is OK in those areas for low
and high band VHF and UHF switching are OK. When monitoring
the tuning voltages generated from the Quad OP amps in U17501(5,6,7,& 8) we
found that pin 5 was the lowest voltage of all of the other pins. These is
the tuning voltages for all the vaircaps in the tuner area. Pin 5 it
the tuning voltage for the Local oscillator. It never went higher than 1
volt no mater what channel was selected. Checking the resistance to ground
on pin 5 we found it to be less than 1k it should be in the 20 megs +.
Removing C17508 removed the load on that line and corrected d the fault.
Capacitor PN is 197600 1000 @ 50 vdc SMD.

RCA F27615 CTC197 Chipper Checker Unit operates fine but it does not show
the usage display in the menu provided in the chipper checker dialogue
box.All sets were tried out with the newest version of
Chipper Checker. After loading the new version of the software Chipper
Checker II ver 1.61, It was discovered the screen size in the selected in
the computers display was set to 800X600 instead of 640X48

RCAF32635CTC197CRTF32635S On bright white areas of the screen the screen
temperature will change slightly and slowly return to normalThis is known as
doming and is normal on most all picture tubes. It is caused By the
expansion coefficient effect of the shadow mask inside the tube. As the
bright beam passes through the holes in the shadow Mask the shadow mask
heats up in that geographic area of the mask. Since that area is hotter than
the surrounding area it expands more the cooler surrounding area. This
causes a doming or a blistering effect of the mask causing the "Q" distance
to change. The "Q" distance is the optimum distance between the surface of
the shadow mask and the phosphor dot on the CRT face.

RCA F36673 CTC197 CRT Unit has a blurry picture and arcing in the neck of
the tube. Unable to check the Voltages at on the socket with tube
disconnected due to sporadic arcing from the pins of the CRT A90AEJ15X01
unit has blurry focus and arcing in the neck of CRT

PS32109 CTC197 CRT Unit will not turn on but there is an arcing in the neck
of the CRTUnit has a defective CRT. We will need a RCA approval from Thomson
for this unit. Tube serial #D-YAGA8516 Code date 97-28, CRT # A80AEJ16X09
VLS # TG9194-AF

RCA PS32500 CTC197 Dead Unit is dead will not power up. Unit appears to have
normal data and clock and all B+'s appear to be normal.Unit has DATA Clock,
Reset, B+, on all components that connect to the T-4 chip. Q14301( C) was at
36 volts all the time. It never changed from stand by to run mode. There was
Horizontal drive to Q14301(B) at nearly 2 volts peak to peak. This high
drive voltage indicated that Q14301 base was open, and it had a
emitter/Collector leakage. Replaced Q14301 PN# 146851


PS27500 CTC197 DeadUnit has no standby voltages Secondary B+ is pulsing. All
voltages on secondary are pulsing at about 1/2 of their normal
values.Checking all the silicon components in the primary I found a 10 ohm
short across CR14102. This was caused by a shorted C14147 1.5 mfd @ 100vdc.
Part number 214049


RCA F36674 CTC197 dead Power supply is squealing nothing noticeably burned.
But an ohms check on Q14401 fins a 30 ohm to ground. Checking the following
components we found C14401, and CR14401 & Q14802 shorted. It is suggested
that these and the following components be replaced, C14410, C14800,
CR14800, CR14401.

PS36677 CTC197 DEADF bad flyback transformer Now main B+ current and
horizontal timing pulse
are normal. When power is applied plug-in B+ at collector of horiz out
starts out about 140V, but then runs away to over 170V and resistor R14126
(30K) goes up in smoke. Tech statically checked the surrounding
components, and they checked OK seem to check OK.R14126 is in the snubber
circuit. If that guy blows you will need to replace C14122, CR14122, and
C14128. Back EMF from T14101 is killing this resistor because one of the
components in the snubber circuit has failed. As long as the flyback does
not have a short circuit in the primary winding to ground, the power supply
will produce approx. 165 vdc at CR14106(K) with no load. Static checking the
components listed above will not tell you the true story about their health.
REPLACE THEM!. Note: follow up----The device that was bad is CR14122.

RCA PS27500 CTC197 dead shorted Chopper transistor Q14101 and a open R14145.
These items were replaced but still no operation of the SMPS.It is a mystery
why the resistor R14145 would be open and the FET Q14101 too. It is possible
the set may have been hit with a line surge taking out the R14103 too. What
is known is the set has no stand by voltages and no noise from power supply.
Unit had defective Q14101, R14145 & R14103. Replacement corrected the fault.

RCA PS27500 CTC197 dead shorted Chopper transistor Q14101 and a open R14145.
These items were replaced but still no operation of the SMPS.It is a mystery
why the resistor R14145 would be open and the FET Q14101 too. It is possible
the set may have been hit with a line surge taking out the R14103 too. What
is known is the set has no stand by voltages and no noise from power supply.
Unit had an open in the trace
from the R14103 to pin U14101(6)

RCA PS32109 CTC197 dead Unit will not power up. No LED flashing in front.
When checking the standby voltages from the output of the SMPS we found the
supply has all stand by sources except the 16 volt source from CR14107.
Further inspection finds that CR14107 has a severed leg at the body of the
device hidden by its ferrite bead.

RCA PS32500 CTC197 dead No secondary supply voltage in the stand by mode.
All raw DC voltages are
there in the primary sideAll primary voltages of power supply are present
with the exception of U14101(3) which was "0" volts DC. This is one of the
initial start up voltages for the Power Supply regulator IC. R14145 a 270K
resistor was open in the primary of Power supply. Replacing it corrected the
fault.

RCA PS32500 CTC197 dead No secondary supply voltage in the stand by mode.
All raw DC voltages are
there in the primary sideAll primary voltages of power supply are present
with the exception of U14101(3) which was "0" volts DC. This is one of the
initial start up voltages for the Power Supply regulator IC. R14145 a 270K
resistor was open in the primary OF Power supply

RCA PS32500 CTC197 dead No stand by voltages from secondary of power supply.
No oscillation from SMPS.Checking the e Soft start B+ at U14101((3) finds it
to be "0" volts. D.C. resistance to ground is Approximately 5K (Normal)
R14145 open (270K 1/2 watt) P N #193067

RCA PS32500 CTC197 dead No stand by voltages from secondary of power supply.
No oscillation from SMPS.R14145 open

PS36605 CTC197 Dead Resoldered the tuner for intermittent reception. Now the
set is dead. All stand by
voltages are normal.Checking the DATA and CLOCK lines on U13101(3 & 4) find
they are 13K resistance to ground. The same is true with U17501(18 &19) This
indicates the I2C bus is not shorted or open and nothing bad happened in the
resoldering process of the tuner. I next had the tech cut jumper wire
JW12410 located at LL8 on the deflection circuit board. This turns on all of
the switched Post regulators U14701, U14104, U18101... etc. Once confirming
these regulators were running the next test was to see if U16201(20) had B+.
It must be 7.5 vdc. In this unit the voltage was zero volts. It was
discovered that there was no voltage at R14102. Following the traces to
JW12143 location MM3 finds that one side of the jumper was torn loose from
the trace. This apparently happened during the servicing of the tuner.

RCA PS32500 CTC197 Dead No secondary supply voltage in the stand by mode.
All raw DC voltages are there in the primary side.All primary voltages of
power supply are present with the exception of U14101(3) which was "0" volts
DC. This is one of the initial start up voltages for the Power Supply
regulator IC. R14145 a 270K resistor was open in the primary of the power
supply.

RCA F36674 CTC197 Dead Power supply is squealing. A visual check of the
supply finds nothing noticeably burned. But an ohms check on Q14401 finds a
30 ohm to ground. Checking the following components we found C14401, and
CR14401 & Q14802 shorted. It is suggested that these and the following
components be replaced, C14410, C14800, CR14800, CR14401.

RCA PS32109 CTC197 Dead Unit will not power up. No LED flashing in front.
When checking the standby voltages from the output of the SMPS we found the
supply has all stand by sources except the 16 volt source from CR14107.
Further inspection finds that CR14107 has a severed leg at the body of the
device hidden by its ferrite bead. There was not enough lead to connect it
to the board. Replacement corrected the problem.

PSNPS27500CTC197DeadUnit will not turn on. If the Secondary B+ finds it
pulsing. All voltages on secondary are pulsing at 30% of their
values.Checking all the silicon components in the Primary I found a 10 ohm
short across CR14102. This was caused by a shorted C14147 1.5 mfd @ 100vdc.
Part number 214049

RCA PS32500 CTC197 Dead Unit will not turn on. Unit does not have any action
of LED's on front.U13102(8) the EPROM we find 5 volts but the reset on the
CPU- U13101(51) finds it running at (0) volts instead of 5 volts. Micro is
stuck in reset. Measuring the voltages at the secondary of T14101 finds that
all the voltages at each diode is correct with the exception of CR14107(C)
They should be 15 volts but it was only 8 volts. Checking the voltage at the
filter C14106 finds the voltage is "0" volts. There was a hairline
separation in the trace between CR14107 and the high side of C14106.

RCA PS27500 CTC197 Out of focus band across the screen that related to
contrast in the pictureUnit has
defective CRT. When moving focus control through its range the band get
thicker and spreads wider. Unit has defective CRT

RCA PS27500 CTC197 Out of focus band across the screen that related to
contrast in the pictureUnit has defective CRT

PS35500 CTC197 HIGH VOLTAGE Unit will turn on but not develop high voltage.
When the flash on set is turned on the power led will light up but it will
only flash 3 times then stopLED will flash if there is no high voltage, and
it will try to restart. The collector of Q14401 and Q14301 measures 165 vdc
in the stand by mode. When the set is turned on the voltages drop to 133 &
80 volts respectively. I asked the tech to jumper Q1440


PS35500 CTC197 HIGH VOLTAGE Unit will turn on but not develop high voltage.
When the flash on set is turned on the power led will light up but it will
only flash 3 times then stopLED will flash if there is no high voltage, and
it will try to restart. The collector of Q14401 and Q14301 measures 165 vdc
in the stand by mode. When the set is turned on the voltages drop to 133 &
80 volts respectively. I asked the tech to jumper Q14401(E&B) together and
turn on the set and measure the collector of the Q14301(C ). It was


PS36605 CTC197 HORIZONTAL Unit has a symptom in the video where if vertical
lines were to be displayed on the screen they have a horizontal time base
jitter. The Jitter causes the lines to e broken up into what appears like
dots across a 1/2 wide area from the left and right of the vertical line.
This only appears on the extreme left and right side of the picture and
quickly diminishes as we look at the second and third vertical from the far
sides. I had tech short the Pin modulator diode CR14800, and see if this
symptom disappeared. It did. The trouble is caused by some high frequency
ripple or noise in the pin modulator circuit. Checking with oscilloscope the
source of the E/W pin correction at U16201(17) was very clean. However at
the second output of the dual op amp U14802(7) was very noisy. A slight
parabolic waveform could be seen but had a lot of high frequency noise on
the leading edge of the parabolic wave. Closer inspection of the board found
the C14804 a .027 mfd SMD had fallen off the board. After reinstalling the
capacitor the vaveform cleaned up with almost no high frequency noise.

RCA PS36605 CTC197 horizontal TV has flagging at the top of the screen. This
is intermittent. Horizontal and vertical sync is extracted internally in
U16201. The video must be a minimum of 1 volt pp measured at
U16201(38). This television was only 800 mv. However at the C12710(minus) we
had 1.1 volts pp video, where the other side we only had 0.8 volts. The ESR
of this capacitor was over 150 ohms. Unit had defective Capacitor. C12710

RCA PS32500 CTC197 LINE Unit has bright screen with retrace linesUnit has
200 vdc source voltage from the cathode of CR14702. But on the CRT driver
board a resistor R15108 is burned up. This resistor is attached to theG1
supply for the CRT. It may be possible the CRT arc A80AEJ16X09 tube ser
D-WBLTG055 code date L28GE17. DOP is 1-17-99.

PS36605 CTC197 PIP When the PIP is turn on the PIP has a sever stretch to it
and will not correctly position itself using the remote control. The Square
box for the PIP gets stretched across the screen when trying to move to the
opposite side of the screen.U18101 is the only thing that will cause this
problem It is the F2PPIP chip. It handles all PIP insertion functions, Comb
Filter operations for both PIP and Main. Tech changed U18101 and solved the
trouble.

RCA PS36700 CTC197 PIP Unit operates fine intermittently but the lower
portion of the screen has a 50 IRE bar that matched exactly the size of the
PIP box. When the PIP box is invoked and moved up the screen the 50 IRE bar
moves with it.Because of the thorough description of this symptom it appears
the trouble must be in the FPIP IC U18100. This IC is used for the PIP and
comb filter for both main and pip video.

RCA PS32500 CTC197 REMOTE. Unit has no remote control functions. Unit has
all functions on the front panel keyboard. When checking the Data out of the
IR receiver all we are getting is a 5 volt high. No part number is listed
for this item in the ESI or parts finder software. Unit has defective
IR13401 IR receiver part number 245282. This is the all plastic opaque type

RCA PS32500 CTC197 remoteUnit will not operate with remote. All functions
operate on front panel keyboard.Unit has all functions on the front panel
keyboard. When checking the Data out of the IR receiver
all we are getting is a 5 volt high. No part number is listed for this item
in the ESI or parts finder software. Unit has defective IR13401 IR receiver
part number 245282. This is the all plastic opaque type

RCA PS36500 CTC197 REMOTE Unit has poor remote sensitivity. MK2198. Unit was
serviced before for the same trouble but it appears it was not corrected.If
the IR. receiver is pulled out from inside the television the remote control
works fine. Observing the cabinet opening where the IR. light, from the
outside world comes from we find a solid piece of plastic covering any type
of lens of IR. band pass filter that might be built into the cabinet. It is
unclear how this IR. information is getting to the IR. receiver if the area
exposing the IR.
receiver is shadowed by a solid black piece of plastic. Tech need to order
the mask assay. MK2198. But when the Mask came in the piece that held the
IR. sensor was missing from the Mask assembly.. Called Larry May at RCA the
part number of what we need is 243585.


RCA PS32500 CTC197 Unit has no remote control functions. Unit has all
functions on the front panel keyboard. When checking the Data out of the IR
receiver all we are getting is a 5 volt high. Unit has defective
IR13401 IR receiver part number 245282.

PS27500 CTC197 shutdown Unit will not turn on unless we forcing the set on
by entering the service mode. When the error codes are 128, in P1, P2, P3.
This indicates the audio decoder failureChecking the B+ to the U11600(22) we
found only 1.1 vdc on this chip. At the Q11600(E) had only1.1 volts and
Q11600(B) was 1.3 volts. It was discovered that C11629 located at the base
of Q11600 the 9 volt regulator turned into a 42 ohm resistor.

RCA PS36500 CTC197 SHUTDOWN Unit goes into immediate shut down at power up.
Checking the high voltage the set will develop high voltage but will shut
off and cycle on and off. If we disable the horizontal output transistor and
try again, the set , obviously not achieve high voltage but it should stay
on and provide a horizontal drive signal unit the set is turned off. This
was not the case here. The set continued to cycle on and off and provided
good horizontal drive at Q14301 horizontal driver transistor. U13101(37) is
the only pin that never goes high when training book says it must be 5 volts
in the run mode. When checking the other CPU "Must Haves" we find nothing
unusual. All B+ sources for stand by and run are normal. Unit approved for
IFS


PS27600 CTC197 Unit will intermittently shutdown and my not be able to turn
back on for hours. The set will not record any error codes.It was by chance
that we were monitoring the reset pulse at U13101(51). This
line went low and did not return to normal 5 volts unless we heated the area
around 1 ~5 & A ~ E. These are located on the corner of the CBA. Checking
the reset transistors finds that Q13503(B) was at .6 volts
keeping the reset on U13101(51) low. Checking back to find he source of the
0.6 volts we found the voltage was increasing as we got further away from
Q13503. We finally measured both sides of C13504 ad found that both sides
had voltages 5 volts on one side an 3.3 on the other. Capacitor is a .1 mfd
at 50 volts PN# 190552. Replacing it and cleaning off the red glue corrected
the problem.

PS32600 CTC197 No tuning All snow. Determined that the unit was band
switching. Checked for 33v supply at pin 4 of PLL chip (U17501), "0" volts.
Checked 18 ohm 2watt resistor R14159 for open. Resistor was good. Had 140
volts on one side and next to nothing on the other. Checked resistance

PS32600 CTC197 No tuning All snow. Determined that the unit was band
switching. Checked for 33v supply at pin 4 of PLL chip (U17501), "0" volts.
Checked 18 ohm 2watt resistor R14159 for open. Resistor was
good. Had 140 volts on one side and next to nothing on the other. Checked
resistance of pin 4 U17501 and found it to be 63 ohms to ground, (sounds
like me trouble). Eliminated u17501 by lifting pin 4, also lifted several
other parts off of the 33v line. Finally found that the short was
originating from the pip tuner. The 33v is fed to both tuners. By
disconnecting the plug restored normal tuning to unit, thus verifying that
the main tuner was ok. Continued to check for shorts......Found shorted SMD
C17407 on the 33v line on the pip tuner board. Replaced and restored normal
operation to entire set. Fix: Replace shorted C17407, part# 197600.

RCA F36674 CTC197 Tuner gain Unit is getting a blank screen stating the
words "Weak Signal" Unit is getting Video to the input of U26901(6) but
nothing out on U26901(13). I asked the tech to enter the TV GUIDE plus set
up mode and read me the options in the set up dialogue. When the tech got to
the part of the set up that discussed "Do you have a VCR?" It had been
selected and it was available on Video 1 only. Unit has TV Guide set up
incorrectly. I had the tech enter an illegal zip code (99999) and tell the
set up the No DSS, no VCR, and No cable box is present. The illegal zip code
will cause a auto reset of the TV GUIDE Plus
module and will remove it's hold on the chassis tuner. This corrected the
problem. Now the tech will need to reset up the TV GUIDE PLUS correctly.

RCA PS27600 CTC197 TUNING Unit has a problem where all the channels it
receives is off frequency. AFT will not pull it inTech needs to look at the
value of the IF VCO in the Chipper Checker menu. This value can be
moved up or down as much as 10 digits to see if the effect is will correct
the symptom or not. Moving the value of this setting does not change the
symptom.

RCA PS27115 CTC197 TUNING Unit does not have reception above channel 50.
Previous tech from another service center out and resoldered tuner. After
tech left and the customer tried to use the set they discovered no reception
above channel 50Q17504(C) . These are band switching transistors and will
inhibit the operation of the tuner above channel CATV 50. Unit did have a
open Q17504.

RCA PS32500 CTC197 TUNING Unit has no reception on any channels. The number
changes but nothing else on the screen but snow. There is a difference in
the amount of back ground noise when a channel is
selected to the different bands with in this tuner.. Checked all the TV
guide plus setup data found that all was correct. Further hardware checking
found the Cathode of CR14115 (location 20 MM) only 4 volts. This
is supposed to be the 33 vdc line for the tuner. Measuring the resistance to
ground found it to be varying from "0" ohms to 27K while flexing chassis.
Removing tuner shield revealed FB17203 (CBA location L19) a
ferrite bead next to the tuner shield had a solder splash on it causing a
short to the tuner shield and pulling the 33 vdc source to ground.

PS32500 CTC197 TUNING When running the set over a long period of time the
set will go to snow then back to normal after a fraction of a second. The
only error code that can be read is error 21. This is not a valid error
code. Technician resoldered the tuner grounds without effecting the symptom.
Recommend the tech go back and resolder the PLL and Mixer/Osc U7501, U7301
in the tuner assembly. These are both surface mounted capacitors. The
process is to be sure the chassis is totally level, and paint solder flux on
both IC's. Resolde the pins by wiping the solder from the chip to the tip of
the leg in strokes. Once this is accomplished then the tuner is thoroughly
cleaned with flux remover or solvent and a stiff short bristle brush made of
natural material. NO PLASTIC BRUSHES!!!!!

RCA PS32500 CTC197 TUNING Unit takes too long to direct access channels.
Will not aurtoprogram.This delay in direct accessing the channel is too
long.. It should be about 125 milli seconds. The tech needs to
enter the alignment parameters of the IF and see that the IF-VCO parameter
is 98 and the AFC OFFSET is 24. Next is to exit out of the service mode and
disconnect the Chipper Checker. Turn on the set without an antenna connected
and select a low band VHF channel from 2 ~ 6 and wait for 10 seconds. This
allows the CPU to time out and will stop searching for a signal from the
tuner. Next connect the antenna to the television and monitor the voltage at
U16201(12) It must be 3.8 volts. If not, adjust L12302 CCW for 3.8 volts. If
the voltage jumps radically replace L12302 part# 215502. In this test unit
we did have a defective L12302.


PS32600 TUNING CTC197CK Unit does not have high band VHF channelsUnit does
not have band switching from Low band VHF to High band VHF. There is correct
band switching at U17501(17) but no change in level at the collector of
Q17503( C). The collector is always -11.5 volts. When tech was indicating
there looks like a component missing at coordinates K 19. Checking the
voltages at Q17503(B) finds the voltage swing from channe6 to channel 7 is
11.8 to .1 volts. This swing is too far for this PNP transistor. There
should only be a .7 volt drop with respect to the emitter. Unit has a
defective Q17503. After the transistor was not soldered

RCA PS27600 CTC197 TUNING Unit takes too long for the picture to lock in on
channel when direct accessed. Also auto programming does not work. When
measuring U16201(12) we find the voltage to be 5.3 volts. It should be about
2.9 volts. This voltage is the AFT crossover voltage. To set this correctly
you must disconnect the antenna and direct access a local channel strong
enough to receive but not strong enough to receive without an antenna.
Direct access this channel and wait for 10 seconds then connect the antenna.
Measure the voltage at U16201(12) It should be 2.9 volts. If not adjust coil
L12302 so the voltage at (16201(12) is approximately 2.9 vdc. If this
voltage can be achieved then try to autoprogram the unit. In this unit the
original voltage was too high and was brought back to normal with a small
tweak of L12302. Unit is
functioning fine.

RCA PS27500 CTC197 Tuning Unit will not get channels from 7 to 13 plus most
of the other CATV channels, yet the low band VHF is perfect. Checking the
output of U17501(17) and switching the channel from 6 to 7, the voltage will
swing from 11.7 volts on channel 6 to "0" volts on channel 7. But when
checking the voltage at Q17503( C) we found the voltage to be always -11.6
volts no matter what band we were on. It should have swung to a +12 volts on
high band VHF. Transistor Q17503(B) never changed either. Base and emitter
voltage was always the same. But the transistor did not measure shorted.
However replacing the transistor corrected the problem. Part number 215496.
This is a PNP surface mounted transistor.

RCA PS27500 CTC197 Tuning Unit will not get channels from 7 to 13 plus most
of the other CATV channels, yet the low band VHF is perfect. Checking the
output of U17501(17) and switching the channel from 6 to 7, the voltage will
swing from 11.7 volts on channel 6 to "0" volts on channel 7. But when
checking the voltage at Q17503( C) we found the voltage to be always -11.6
volts no matter what band we were on. It should have swung to a +12 volts on
high band VHF. Transistor Q17503(B) never changed either. Base and emitter
voltage was always the same. But the transistor did not measure shorted.
However replacing the transistor corrected the problem. Part number 215496.
This is a PNP surface mounted transistor.


Proscan PS36500 CTC197 tuningUnit has no UHF or CATV reception above channel
50 on the main tuner. However the PIP tuner works fineChecking the
bandswitching at U17501(14) finds the bandswitching is fine when switching
from CATV channel 50 to 51, but when checking Q17505(C ) the voltage is
always 11.5 volts. Q17503(B) swings from 0 to 11.2 volts during
bandswitching. Transistor Q17405 is defective. Part # 231534. This is a
digital transistor and it checked open using the diode check mode on a Fluke
77.

RCA PS32500 CTC197 TURN-ON INOPERATIVE Unit will not turn on. Unit does not
have any action of LED's on front.U13102(8) the EPROM we find 5 volts but
the reset on the CPU- U13101(51) finds it
running at (0) volts instead of 5 volts. Micro is stuck in reset. Measuring
the voltages at the secondary of T14101 finds that all the voltages at each
diode is correct with the exception of CR14107(C) They
should be 15 volts but it was only 8 volts. Checking the voltage at the
filter C14106 finds the voltage is "0" volts. There was a hairline
separation in the trace between CR14107 and the High side of C14106.

RCA PS36700 CTC197 TURN-ON INOPERATIVE Unit will not turn on. Television has
all of the necessary voltages at the System control and standby supplies.
U13101(19) never goes high when the power is
pressed. Unit cannot be forced on By pressing and hold menu, Then power then
volume up then release

PS32500 CTC197 TURN-ON INOPERATIVEUnit will run for a while until the set is
turned off. Once off then turned on again the set will not turn on. No LED
illumination or auto start attempts will occur until 30 to 40 seconds of
wait time. After this wait time the set will turn on just fine. No other
malfunction. Error codes in tech menu indicate error 16 stuck bus.Checking
the "Run" Data and clock signals during the power up sequence we found the
set did not correctly start up with clean signals. There were signals within
the 5 volt peak to peak
pulse train that were lower than the bulk of the pulse train. By
substitution U18100 F2PIP chip was causing the trouble.

PSNPS36500CTC197tURN-ON INOPERATIVEUnit will not turn on. Pushing the
power button makes (U13101(19) go high, but he TV still will not turn on.
While checking the "RUN" data/clock lines on U13101(3&4) we discovered the
data line was running at 1.9 volts peak to peak not the 5 volts
pp.Unplugging the TV and measuring the resistance to ground on the
U13101(4) "RUN Data line finds it to be 1.8K verses the clock line (3) at
13K.. Measuring the resistance to ground at each peripheral the uses the
"RUN" data line we found the resistance drop to 745 ohms at Q18102(c ).
Removing this service mounted transistor caused the solder land for the
collector to go to 13K. Replacing the device corrected the trouble. Part #
219412. This is a NPN SMD transistor.

RCAF32645CTC197TV GUIDE PLUSF32645 Serial 520287768 Customer operates
television on a satellite system. He is too far from the city to receive
local television and is not supported by CATV. Customer does not want TV
Guide to operate.There is no was to disconnect the TVG from the set that
Thomson will approve, but the tech can enter and illegal zip code into the
system and cause it to shut down. And illegal zip code could be 99999.
This should stop it from trying to download anything.

RCAPS32600CTC197TV GUIDE PLUSPS32600 serial 912631148 TV guide plus does
not load data. In the TV guide set up mode the customer answered yes to
the VCR. He should not unless he is using their blaster to communicate to
the VCR. Cust does not have the IR blaster. So the answer to all the
question in the TV guide plus set up must all be "NO". I order for the
tech to do this he must enter a zip code of 99999, then finish the setup
process. Wait for 5 minutes, at which point the set will default to an
error condition due to the illegal Zip code. Then enter the correct Zip
code and wait for the next down load time.

RCAPS32700CTC197TV GUIDE PLUSPS32700 serial 836531479. Unit will not
download the TV guide Plus info to make the VCR recordI had tech reset the
TV guide module by entering the Guide plus setup program the hitting the
"Go back" button on the remote then hit the "TV" button twice. This clears
the old data in the system and starts a internal test program. It will
check the ROM, RAM, VBI, and G-LINK. All passed except the VBI and Glink.
The VBI did not pass because it was not on the host channel. The Glink did
not pass possibly because the Glink cable is defective or a bad IR blaster
at the end of the G-link cable. The G-link is necessary for VCR
programming because the television will turn on the VCR via the G-link
cable and IR blaster, make the VCR select the channel, and place it in the
record mode. Apparently the TV guide plus module was connected
incorrectly. The connector J23905 was connected to the front video line
input. There does not appear to be any cable from J23905 to J26401. Tech
will need to hard wire a jumper from J23905(1) to J26401(2) J23905(2) to
J26401(1) Note: these are opposite from each other.

RCAPS36500CTC197TV GUIDE PLUSPS36600 serial 846331490. Unit does not
always download TV guide plus data. Customer has a VCR, and is on cable
TVThe customer has the VCR connected in series with the R.F. path where
the CATV from the street goes into the VCR then out of the VCR to the
Television. Customer must watch the VCR on channel 3. This is not the best
hook up of the VCR in this application. When used in this manor the
customer must used the IR blaster that came with his television. This way
the TV will control the VCR through the IR blaster and the TV will
download the Gemstar data by using the VCR tuner. One drawback from this
configuration is the VCR needs to be on all of the time, and the TV will
always be on channel 3.

PSNPS36500CTC197VERTICALPS36500 Unit has no vertical sweep. The horizontal
line is elevated 2 inches above center. Monitoring the yoke voltage we
found 23 volts. Also the 13 volt supply was at 22 volts. However when
disconnecting the vertical yoke winding the 13 volt voltage return to
normalChecking the vertical output for damaged or burnt components found
nothing. But when heating the area around the T-4 chip U16201 we found
that components in the area where vertical drive comes from full sweep
returned. Spot heating of C14501 & C14503 caused the vertical sweep to
return. Removing the capacitors and cleaning the component adhesive the
capacitors and Board are defective

PSNPS36700CTC197VERTICALPS36700 Unit has vertical over scan and the
picture is tilted. Tech needs to know where the parameters are that
control this values.Suggest the tech get into the customer menu and select
screen. Once in the screen menu select Picture tilt. Adjust PIX tilt so
the image is level. Next Enter the tech menu and select the parameter 10 &
11or vertical centering and vertical size. Adjust for normal scan and turn
the set off. This action will store the values.

PS36605CTC197verticalUnit has weak vertical sync lock. Horizontal
OKHorizontal and vertical sync is extracted internally in U16201. The
video must be a minimum of 1 volt pp measured at U16201(38). This
television was only 700 mv. However at the C12710(minus) we had 1.1 volts
pp video, where the other side we only had 0.7 volts. Unit had defective
Capacitor. C12710

RCAF36670CTC197verticalUnit made a loud squeal in the back of the set then
the vertical sweep became very distorted. The bottom of the picture was
pulled up and the top very stretched. Tech needs to check the presence of
the "Half voltage supply" a 13 volts supply at the flyback. Unit had a
shorted CR14703 =207878(large) and a open R14705= 829A10. This supply
provides the necessary bias for the input of the vertical output IC.

PSNPS36500CTC197videoPS36500. Serial # 927631446 Unit has intermittently
looses video but still has sound. Does not have the symptom if using the
External video input. Suggest the tech look at the Input switching area
for the trouble. Assuming the set never looses the video when running in
the External input mode, and the set still has sound it logically limits
the possibilities to The input switch U26901. This IC is responsible for
the routing of 4 different video sources from 4 different inputs. If
everything works in the Video input mode and in the tuner mode there is no
video then It would suggest the trouble is located in the Switching IC.
(Based on the techs initial observation that the set had audio in the
tuner mode.

PSNPS36700CTC197VideoPicture contrast is abnormal in a band that covers
the bottom 1/3 of the screen. This can be seen in the oscilloscope when
viewed at U18101(41) when looking at the vertical rate 2 milli seconds.
Pattern generator was set to gray scale vertical bars. Comparing the video
at U18101(51) to pin 41 the difference was significant.Unit has an
artifact that matched the window position for the PIP frame. It caused the
transparent horizontal band at the bottom 1/3 of the screen. It was on all
inputs. This was caused by the F2PIP chip. Part # 248640

PSNPS27500CTC197video 1 missingUnit has no video when using the video 1
input. We were able to track composite video from the video input of
U26901(3), however nothing on the output side U269011(13).Monitoring
composite to the input of the FPIP U18100(51) is OK. But there was no
output on Pin 41. Oddly enough when we fed video into the Video 2 it
worked as expected. Also Tuner mode operated fine. On other significant
symptom not complained about was this TV did not have video in the S-video
input. We could trace the Luminance from the S-video input to each side
C26916, but nothing at he Input of IC18101(3). It was discovered that
C18105 was open. Replacing the capacitor corrected both symptoms, both
S-video and Video 1. The explanation of this phenomena was because the
S-video input was essentialy open because of the open capacitor the F2PIP
automatically switched to the input selector to S-video instead of video
1. The design of the F2PIP chip senses activity on U18101(3) and it
automatically switched inputs. This input was unterminated and noise got
into the inout falsing the internal switch.

PSNPS27500CTC197VIDEO NOISEPS27500 serial 849631568. Unit has heavy black
and white horizontal dashes on the screen that are 3 to 4 inches long,
that cover the entire screen. It does have On screen display and menu
functions. I hade the tech check the luminance out of U18100(41) We had a
saw tooth waveform nearly 1 volt peak to peak at 3 micro seconds period.
This could also be seen at the input U18100(51). However the Output of the
video switch U26901(13) was clean video. It was discovered that video was
clean up to BPF circuit after Q18110(E) Capacitor C18101 was broken.

No Video After Changing Flyback  I get the OSD and audio but no video signal
from the main tuner just a blank raster. Screen voltage is OK. I get video
in the PIP window but when I swap pictures the main screen stays blank and
only the audio
changes. The jumper bewtween pins 7 & 8 of the fly is good.
A: Was the old fly arcing ? If so it probably damaged the video circuit. The
way PIP is accomplished in alot of sets makes it immune to ABL, which is the
path by which the fly can do any damage. Even more common is the OSD not
being affected by ABL.
With a print you're looking for the pin of the fly at the bottom end of the
high voltage secondary. Without a print you're looking for a pin on the fly
with a cutout in the PC board to isolate it. This is so if the fly secondary
arcs it won't cause a carbon track on the PCB and it also lessens the
possibility of fire. There should usually be a reasonable positive DC
voltage there. Some older sets would have the B+ on that pin and be
resistored down for control of the video, but newer sets use dynamic ABL
that is not clamped in normal operation. If you see 0V or a negative voltage
there you are very close to the problem. Once you run it down and get your
video back, view a high contrast fast moving scene with the picture cranked.
You might even want to temporarily crank up the sub contrast, which you of
course return to the old setting when you're done. What you are looking for
then is compression and rarification of the raster lines. This dynamic ABL
is used for sweep correction. On a direct view it usually goes to the
vertical and video. Some projection sets also send it to the E-W pincushion
as well and sometimes the integration network is a bit complex.
If you lack a print, get the datasheet for the jungle (LA7612 ?) and work
back from there as well. While you might have a shorted cap near the fly (in
the circuit) it is also possible it zapped something that either amplifies
or buffs the ABL line. The first check I would do is the resistance from the
ABL pin to ground. If it's shorted start unsoldering stuff from it, or if
you happen to have a low ohms meter you can find it that way. In a nutshell,
I'd say it's a 99% chance or better that the problem is in the ABL
somewhere. I'd go there unless you don't have sync. In case you don't know
how to test for sync, the OSD will move if you remove the input signal. Just
FYI if you don't have any OSD you turn up the G2 so you can see retrace
lines and watch their behaviour when you apply
or remove a valid video signal. You might not have to even bother, if the
PIP image is stable you got sync usually.

ProScan Chassis CTC197CG Model PS36125 Resolder the little coil between the
HDT and the HOT. You usually cannot see the bad connection. I found it the
first time with a scope. Can cause HOT transistor to fail

CTC197 Intermittent audio. Video OK, All functions OK. Removing and
reapplying power restores audio This trouble is caused by a defective data
packet broadcast from a local TV station. The data packet is located in the
VBI (Vertical Retrace Interval). It's purpose is for XDS (Extended Data
Services) that is used by the GemStar circuitry. The condition is very
intermittent and not much is known to the average TV technician because
Thomson is not releasing much information to the public other than removing
the power and reapplying it again. Thomson's answer to this issue is taking
their case to the FCC and let them resolve the conflict between FCC and the
broadcasters. This phenomena only effects certain Thomson chassis CTC197,
CTC195 and CTC203. Only a specific run of serial numbers are affected.


Robert McPherson
Computer & Television Service
1322 Durrett Lane Louisville, KY 40213
Telephone (502) 367-9324 Cellphone (502) 298-6997
Email  rm502@xxxxxxxxxxxxx

----- Original Message ----- >
> Can someone send me some of the common repairs to a Ctc 197 chassis.
> The set Tries to start and makes a strange sound but does not come up.
> and  no sound.
> Picking up the set tomorrow  for repair.
> THe set I believe is a 36" RCA CTC 197
> MOdel # at this time is ?.
>
> Thanks Guys
> Warren Campbell
> Campbell's TV & Appliances
> --------------------------------------------------------------------------
---


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