Proscan PS56670 / Chassis CTC195 Issues

[Andy]

I bought my Proscan 56" RPTV (model PS56670LG1, Chassis PTK195CP or
CTC195C) back in 1997. Within 6 months, I was experiencing
intermittent picture quality issues, such as the picture going to all
snow, and the audio making loud hissing/crackling sounds. Each
"event" would last approximately 1 minute, then the picture would
return to normal. I made the faulty assumption that I simply had
reception issues with my cable, and did not pursue a problem within
the TV itself. As a result, the problem has escalated into other
areas of the chassis. The picture is now very fuzzy, the convergence
is way out, and the picture is bowed at the top and bottom of the
screen.

I am not a TV repairman, I'm an Engineer, but I used to repair TV's on
the side while I was in college, so I have a fundamental understanding
of electronic repair. I have the Chipper Check II system (ver 1.83a)
[which, by the way, is not displaying properly on my 1 year old
computer running XP - TCE says I have my fonts set incorrectly, but
every possible font size doesn't remedy the issue.] Chipper Check was
able to read the Main EEPROM without problem, the PIP Tuner EEPROM
without problem and supposedly, the Digicon EEPROM without
problem-although the Digicon EEPROM came back with all FF's in each
parameter.

Also, during the I2C check, Chipper Check was able to communicate with
all components except it came back with the message: "Convergence
Module did NOT respond on the Run bus." [It also came back with the
message: "YPrPb Processor, U22303, did NOT respond on the Run bus."
But, I'm not certain that my chassis has the YPrPb Processor
installed--I was unable to find it.]

From reading the many comments on this site regarding the CTC195
chassis, I measured the output voltage of the Convergence Power Supply
at the connector (J19701) and discovered the voltages were not as
published. The voltages at each pin were approximately 17 volts to
the ground pin (pin 3). I then pulled the Convergence Power Supply
connector and it did not effect the picture. I plugged the power
supply connector back in and the picture jumped a little bit, but did
nothing more.

I don't know if the voltage errors are a result of some failure in the
convergence power supply, or the convergence module or both. I have a
copy of the "Basic Service Data" First Edition - First Printing dated
1997. This was published long before the historical issues with this
chassis become known, so I have none of the Service Bulletins and
Service Kits later made available.

I've noticed that many of you have extensive experience with this
chassis, and also that many of you have a great passion for your work,
so I'd love to hear your recommendations for repairing this TV.

Thank you,

Andy McClellan

 

[Art]

Convergence power supply problem, probable pincushion problems, and a
defective tuner assemnbly. Convergence power supply and tuner are available
as assemblies from an RCA Parts Supplier. Pincushion may be just a diode and
cap in the pcc circuitry, common failure. Very probable not an E_Prom or
data related problem. Tuner should have a part number wither inked on it or
afixed to a white paper adhesive tag. Convergence power supply probably can
be ordered by description with the correct CTC169XXX numbers.

I bought my Proscan 56" RPTV (model PS56670LG1, Chassis PTK195CP or
CTC195C) back in 1997. Within 6 months, I was experiencing
intermittent picture quality issues, such as the picture going to all
snow, and the audio making loud hissing/crackling sounds. Each
"event" would last approximately 1 minute, then the picture would
return to normal. I made the faulty assumption that I simply had
reception issues with my cable, and did not pursue a problem within
the TV itself. As a result, the problem has escalated into other
areas of the chassis. The picture is now very fuzzy, the convergence
is way out, and the picture is bowed at the top and bottom of the
screen.

I am not a TV repairman, I'm an Engineer, but I used to repair TV's on
the side while I was in college, so I have a fundamental understanding
of electronic repair. I have the Chipper Check II system (ver 1.83a)
[which, by the way, is not displaying properly on my 1 year old
computer running XP - TCE says I have my fonts set incorrectly, but
every possible font size doesn't remedy the issue.] Chipper Check was
able to read the Main EEPROM without problem, the PIP Tuner EEPROM
without problem and supposedly, the Digicon EEPROM without
problem-although the Digicon EEPROM came back with all FF's in each
parameter.

Also, during the I2C check, Chipper Check was able to communicate with
all components except it came back with the message: "Convergence
Module did NOT respond on the Run bus." [It also came back with the
message: "YPrPb Processor, U22303, did NOT respond on the Run bus."
But, I'm not certain that my chassis has the YPrPb Processor
installed--I was unable to find it.]

From reading the many comments on this site regarding the CTC195
chassis, I measured the output voltage of the Convergence Power Supply
at the connector (J19701) and discovered the voltages were not as
published. The voltages at each pin were approximately 17 volts to
the ground pin (pin 3). I then pulled the Convergence Power Supply
connector and it did not effect the picture. I plugged the power
supply connector back in and the picture jumped a little bit, but did
nothing more.

I don't know if the voltage errors are a result of some failure in the
convergence power supply, or the convergence module or both. I have a
copy of the "Basic Service Data" First Edition - First Printing dated
1997. This was published long before the historical issues with this
chassis become known, so I have none of the Service Bulletins and
Service Kits later made available.

I've noticed that many of you have extensive experience with this
chassis, and also that many of you have a great passion for your work,
so I'd love to hear your recommendations for repairing this TV.

Thank you,

Andy McClellan

 

[David]

Your set has an onboard tuner and is not replaceable by itself. Odds are
the set since it was made in 1997 has several service bulletins that need
applied before doing any thing else.

If the convergence power supply voltages are close, you have a problem on
the convergence main board. Most likely a problem with the can shorting the
5v line to the convergence syscon (another service bulletin), or a problem
with glue that has become conductive on either the 5v line or the clock and
data lines, SDA,SCL.

The tuner issues are also likely either a service bulletin or conductive
glue under c15703and c15704, both surface mount capacitors will need
removed, the solder and glue cleaned up, then replaced.

Secondly, you cannot always reliably run Chipper Check on newer faster
machines, you need to get a hold of an older, preferably slower than 333Mhz.
Yes, you probably do need to change font size, etc. I am not sure your
Chipper Check software version is tested 100% compatible with XP.

You have multiple issues to address, start with the convergence issue first,
Check ALL applicable service bulletins and apply all of them, then deal with
the snowy picture issue.

Be forewarned, if you are not 100% comfortable and competant working with
tightly packed surface mount components and fully equipped with good
soldering and desoldering equipment, odds that you will do more damage
increase greatly. It is simply way too easy to damage surface mount stuff
on that board, even pulling the thin board out carelessly can flex it enough
to crack some surface mount parts!!!!

David

I bought my Proscan 56" RPTV (model PS56670LG1, Chassis PTK195CP or
CTC195C) back in 1997. Within 6 months, I was experiencing
intermittent picture quality issues, such as the picture going to all
snow, and the audio making loud hissing/crackling sounds. Each
"event" would last approximately 1 minute, then the picture would
return to normal. I made the faulty assumption that I simply had
reception issues with my cable, and did not pursue a problem within
the TV itself. As a result, the problem has escalated into other
areas of the chassis. The picture is now very fuzzy, the convergence
is way out, and the picture is bowed at the top and bottom of the
screen.

I am not a TV repairman, I'm an Engineer, but I used to repair TV's on
the side while I was in college, so I have a fundamental understanding
of electronic repair. I have the Chipper Check II system (ver 1.83a)
[which, by the way, is not displaying properly on my 1 year old
computer running XP - TCE says I have my fonts set incorrectly, but
every possible font size doesn't remedy the issue.] Chipper Check was
able to read the Main EEPROM without problem, the PIP Tuner EEPROM
without problem and supposedly, the Digicon EEPROM without
problem-although the Digicon EEPROM came back with all FF's in each
parameter.

Also, during the I2C check, Chipper Check was able to communicate with
all components except it came back with the message: "Convergence
Module did NOT respond on the Run bus." [It also came back with the
message: "YPrPb Processor, U22303, did NOT respond on the Run bus."
But, I'm not certain that my chassis has the YPrPb Processor
installed--I was unable to find it.]

From reading the many comments on this site regarding the CTC195
chassis, I measured the output voltage of the Convergence Power Supply
at the connector (J19701) and discovered the voltages were not as
published. The voltages at each pin were approximately 17 volts to
the ground pin (pin 3). I then pulled the Convergence Power Supply
connector and it did not effect the picture. I plugged the power
supply connector back in and the picture jumped a little bit, but did
nothing more.

I don't know if the voltage errors are a result of some failure in the
convergence power supply, or the convergence module or both. I have a
copy of the "Basic Service Data" First Edition - First Printing dated
1997. This was published long before the historical issues with this
chassis become known, so I have none of the Service Bulletins and
Service Kits later made available.

I've noticed that many of you have extensive experience with this
chassis, and also that many of you have a great passion for your work,
so I'd love to hear your recommendations for repairing this TV.

Thank you,

Andy McClellan

 

[Art]

Opps, mis read chassis # thought 169, Duh. brain fart again: LOL <

Agreed on-board tuner has to be repaired.<
E-prom data may need to be reinitialized if you can. That is if the device

has not been damaged due to the lousy grounding within the tuner assembly.<

Been running Chipper Checker on a 1 gig laptop having XP Professional

SP2Beta with absolutely no operational problems. Make sure you have
downloaded the latest updates for Chipper Checker from the RCA Web Site. <

Seen a few problems within the actual convegence circuit board but many

more due to the power supply problems.

Your set has an onboard tuner and is not replaceable by itself. Odds are
the set since it was made in 1997 has several service bulletins that need
applied before doing any thing else.

If the convergence power supply voltages are close, you have a problem on
the convergence main board. Most likely a problem with the can shorting the
5v line to the convergence syscon (another service bulletin), or a problem
with glue that has become conductive on either the 5v line or the clock and
data lines, SDA,SCL.

The tuner issues are also likely either a service bulletin or conductive
glue under c15703and c15704, both surface mount capacitors will need
removed, the solder and glue cleaned up, then replaced.

Secondly, you cannot always reliably run Chipper Check on newer faster
machines, you need to get a hold of an older, preferably slower than 333Mhz.
Yes, you probably do need to change font size, etc. I am not sure your
Chipper Check software version is tested 100% compatible with XP.

You have multiple issues to address, start with the convergence issue first,
Check ALL applicable service bulletins and apply all of them, then deal with
the snowy picture issue.

Be forewarned, if you are not 100% comfortable and competant working with
tightly packed surface mount components and fully equipped with good
soldering and desoldering equipment, odds that you will do more damage
increase greatly. It is simply way too easy to damage surface mount stuff
on that board, even pulling the thin board out carelessly can flex it enough
to crack some surface mount parts!!!!

David

I bought my Proscan 56" RPTV (model PS56670LG1, Chassis PTK195CP or
CTC195C) back in 1997. Within 6 months, I was experiencing
intermittent picture quality issues, such as the picture going to all
snow, and the audio making loud hissing/crackling sounds. Each
"event" would last approximately 1 minute, then the picture would
return to normal. I made the faulty assumption that I simply had
reception issues with my cable, and did not pursue a problem within
the TV itself. As a result, the problem has escalated into other
areas of the chassis. The picture is now very fuzzy, the convergence
is way out, and the picture is bowed at the top and bottom of the
screen.

I am not a TV repairman, I'm an Engineer, but I used to repair TV's on
the side while I was in college, so I have a fundamental understanding
of electronic repair. I have the Chipper Check II system (ver 1.83a)
[which, by the way, is not displaying properly on my 1 year old
computer running XP - TCE says I have my fonts set incorrectly, but
every possible font size doesn't remedy the issue.] Chipper Check was
able to read the Main EEPROM without problem, the PIP Tuner EEPROM
without problem and supposedly, the Digicon EEPROM without
problem-although the Digicon EEPROM came back with all FF's in each
parameter.

Also, during the I2C check, Chipper Check was able to communicate with
all components except it came back with the message: "Convergence
Module did NOT respond on the Run bus." [It also came back with the
message: "YPrPb Processor, U22303, did NOT respond on the Run bus."
But, I'm not certain that my chassis has the YPrPb Processor
installed--I was unable to find it.]

From reading the many comments on this site regarding the CTC195
chassis, I measured the output voltage of the Convergence Power Supply
at the connector (J19701) and discovered the voltages were not as
published. The voltages at each pin were approximately 17 volts to
the ground pin (pin 3). I then pulled the Convergence Power Supply
connector and it did not effect the picture. I plugged the power
supply connector back in and the picture jumped a little bit, but did
nothing more.

I don't know if the voltage errors are a result of some failure in the
convergence power supply, or the convergence module or both. I have a
copy of the "Basic Service Data" First Edition - First Printing dated
1997. This was published long before the historical issues with this
chassis become known, so I have none of the Service Bulletins and
Service Kits later made available.

I've noticed that many of you have extensive experience with this
chassis, and also that many of you have a great passion for your work,
so I'd love to hear your recommendations for repairing this TV.

Thank you,

Andy McClellan

 

[Andy]

Thanks for your response. I'll need to get a copy of the Service
Bulletins. Do you know where I can get a copy? Is there a website
that I can download them from?

I've since checked the heat sinks on the Convergence Power Supply and
the Module itself, and they are both cold. I static checked the
diodes and caps on the power supply and found them looking fine. I
checked voltages at the output connector of the PTV AUX board
(J19701), and the voltages are perfect for about 2 seconds, then they
all drop out except the +23V from the filament. This tells me the
"Current Limiting" is working, and there's probably something wrong on
the Convergence Module either over or under loading the power supply.
I couldn't tell which voltage was tripping the current limiting. I
think it was the -15V line going below -13V, and shutting the power
supply down.

I think your advice is very sound. I'll address all of the service
bulletins first, and see if that doesn't just take care of the
problem. If not, then I'll reassess. As far as my competence working
with SMD's goes, I've never done it, and it looks hard. But, I'm
pretty careful, and the learning factor is awesome, so I'll probably
just keep going until I either fix it, or it fixes me. >:| When it
comes time to replace the SMD's, I might just get intimidated enough
to let a professional do it.

BTW, in order to get the main board out of the TV, I need to
disconnect the High Voltage leads from the splitter, but I couldn't
figure out a way to do this. How is this done? I'm assuming that
they're probably soldered into the splitter, but are they soldered on
both ends?

Also, I got Chipper Check to display properly on an old computer. The
resolution was below what my new computer is capable of. Then I
figured out a way to get it to work on my new computer--in the
Advanced Settings.

Thanks again. If you have information on where I can get a copy of
the Service Bulletins, I'd really appreciate it.

Andy

Your set has an onboard tuner and is not replaceable by itself. Odds are
the set since it was made in 1997 has several service bulletins that need
applied before doing any thing else.

If the convergence power supply voltages are close, you have a problem on
the convergence main board. Most likely a problem with the can shorting the
5v line to the convergence syscon (another service bulletin), or a problem
with glue that has become conductive on either the 5v line or the clock and
data lines, SDA,SCL.

The tuner issues are also likely either a service bulletin or conductive
glue under c15703and c15704, both surface mount capacitors will need
removed, the solder and glue cleaned up, then replaced.

Secondly, you cannot always reliably run Chipper Check on newer faster
machines, you need to get a hold of an older, preferably slower than 333Mhz.
Yes, you probably do need to change font size, etc. I am not sure your
Chipper Check software version is tested 100% compatible with XP.

You have multiple issues to address, start with the convergence issue first,
Check ALL applicable service bulletins and apply all of them, then deal with
the snowy picture issue.

Be forewarned, if you are not 100% comfortable and competant working with
tightly packed surface mount components and fully equipped with good
soldering and desoldering equipment, odds that you will do more damage
increase greatly. It is simply way too easy to damage surface mount stuff
on that board, even pulling the thin board out carelessly can flex it enough
to crack some surface mount parts!!!!

David

I bought my Proscan 56" RPTV (model PS56670LG1, Chassis PTK195CP or
CTC195C) back in 1997. Within 6 months, I was experiencing
intermittent picture quality issues, such as the picture going to all
snow, and the audio making loud hissing/crackling sounds. Each
"event" would last approximately 1 minute, then the picture would
return to normal. I made the faulty assumption that I simply had
reception issues with my cable, and did not pursue a problem within
the TV itself. As a result, the problem has escalated into other
areas of the chassis. The picture is now very fuzzy, the convergence
is way out, and the picture is bowed at the top and bottom of the
screen.

I am not a TV repairman, I'm an Engineer, but I used to repair TV's on
the side while I was in college, so I have a fundamental understanding
of electronic repair. I have the Chipper Check II system (ver 1.83a)
[which, by the way, is not displaying properly on my 1 year old
computer running XP - TCE says I have my fonts set incorrectly, but
every possible font size doesn't remedy the issue.] Chipper Check was
able to read the Main EEPROM without problem, the PIP Tuner EEPROM
without problem and supposedly, the Digicon EEPROM without
problem-although the Digicon EEPROM came back with all FF's in each
parameter.

Also, during the I2C check, Chipper Check was able to communicate with
all components except it came back with the message: "Convergence
Module did NOT respond on the Run bus." [It also came back with the
message: "YPrPb Processor, U22303, did NOT respond on the Run bus."
But, I'm not certain that my chassis has the YPrPb Processor
installed--I was unable to find it.]

From reading the many comments on this site regarding the CTC195
chassis, I measured the output voltage of the Convergence Power Supply
at the connector (J19701) and discovered the voltages were not as
published. The voltages at each pin were approximately 17 volts to
the ground pin (pin 3). I then pulled the Convergence Power Supply
connector and it did not effect the picture. I plugged the power
supply connector back in and the picture jumped a little bit, but did
nothing more.

I don't know if the voltage errors are a result of some failure in the
convergence power supply, or the convergence module or both. I have a
copy of the "Basic Service Data" First Edition - First Printing dated
1997. This was published long before the historical issues with this
chassis become known, so I have none of the Service Bulletins and
Service Kits later made available.

I've noticed that many of you have extensive experience with this
chassis, and also that many of you have a great passion for your work,
so I'd love to hear your recommendations for repairing this TV.

Thank you,

Andy McClellan

 

[Art]

www.thompsonnetwork.com but you will probably need a username and password
to access.

Thanks for your response. I'll need to get a copy of the Service
Bulletins. Do you know where I can get a copy? Is there a website
that I can download them from?

I've since checked the heat sinks on the Convergence Power Supply and
the Module itself, and they are both cold. I static checked the
diodes and caps on the power supply and found them looking fine. I
checked voltages at the output connector of the PTV AUX board
(J19701), and the voltages are perfect for about 2 seconds, then they
all drop out except the +23V from the filament. This tells me the
"Current Limiting" is working, and there's probably something wrong on
the Convergence Module either over or under loading the power supply.
I couldn't tell which voltage was tripping the current limiting. I
think it was the -15V line going below -13V, and shutting the power
supply down.

I think your advice is very sound. I'll address all of the service
bulletins first, and see if that doesn't just take care of the
problem. If not, then I'll reassess. As far as my competence working
with SMD's goes, I've never done it, and it looks hard. But, I'm
pretty careful, and the learning factor is awesome, so I'll probably
just keep going until I either fix it, or it fixes me. >:| When it
comes time to replace the SMD's, I might just get intimidated enough
to let a professional do it.

BTW, in order to get the main board out of the TV, I need to
disconnect the High Voltage leads from the splitter, but I couldn't
figure out a way to do this. How is this done? I'm assuming that
they're probably soldered into the splitter, but are they soldered on
both ends?

Also, I got Chipper Check to display properly on an old computer. The
resolution was below what my new computer is capable of. Then I
figured out a way to get it to work on my new computer--in the
Advanced Settings.

Thanks again. If you have information on where I can get a copy of
the Service Bulletins, I'd really appreciate it.

Andy

Your set has an onboard tuner and is not replaceable by itself. Odds are
the set since it was made in 1997 has several service bulletins that need
applied before doing any thing else.

If the convergence power supply voltages are close, you have a problem on
the convergence main board. Most likely a problem with the can shorting the
5v line to the convergence syscon (another service bulletin), or a problem
with glue that has become conductive on either the 5v line or the clock and
data lines, SDA,SCL.

The tuner issues are also likely either a service bulletin or conductive
glue under c15703and c15704, both surface mount capacitors will need
removed, the solder and glue cleaned up, then replaced.

Secondly, you cannot always reliably run Chipper Check on newer faster
machines, you need to get a hold of an older, preferably slower than 333Mhz.
Yes, you probably do need to change font size, etc. I am not sure your
Chipper Check software version is tested 100% compatible with XP.

You have multiple issues to address, start with the convergence issue first,
Check ALL applicable service bulletins and apply all of them, then deal with
the snowy picture issue.

Be forewarned, if you are not 100% comfortable and competant working with
tightly packed surface mount components and fully equipped with good
soldering and desoldering equipment, odds that you will do more damage
increase greatly. It is simply way too easy to damage surface mount stuff
on that board, even pulling the thin board out carelessly can flex it enough
to crack some surface mount parts!!!!

David

I bought my Proscan 56" RPTV (model PS56670LG1, Chassis PTK195CP or
CTC195C) back in 1997. Within 6 months, I was experiencing
intermittent picture quality issues, such as the picture going to all
snow, and the audio making loud hissing/crackling sounds. Each
"event" would last approximately 1 minute, then the picture would
return to normal. I made the faulty assumption that I simply had
reception issues with my cable, and did not pursue a problem within
the TV itself. As a result, the problem has escalated into other
areas of the chassis. The picture is now very fuzzy, the convergence
is way out, and the picture is bowed at the top and bottom of the
screen.

I am not a TV repairman, I'm an Engineer, but I used to repair TV's on
the side while I was in college, so I have a fundamental understanding
of electronic repair. I have the Chipper Check II system (ver 1.83a)
[which, by the way, is not displaying properly on my 1 year old
computer running XP - TCE says I have my fonts set incorrectly, but
every possible font size doesn't remedy the issue.] Chipper Check was
able to read the Main EEPROM without problem, the PIP Tuner EEPROM
without problem and supposedly, the Digicon EEPROM without
problem-although the Digicon EEPROM came back with all FF's in each
parameter.

Also, during the I2C check, Chipper Check was able to communicate with
all components except it came back with the message: "Convergence
Module did NOT respond on the Run bus." [It also came back with the
message: "YPrPb Processor, U22303, did NOT respond on the Run bus."
But, I'm not certain that my chassis has the YPrPb Processor
installed--I was unable to find it.]

From reading the many comments on this site regarding the CTC195
chassis, I measured the output voltage of the Convergence Power Supply
at the connector (J19701) and discovered the voltages were not as
published. The voltages at each pin were approximately 17 volts to
the ground pin (pin 3). I then pulled the Convergence Power Supply
connector and it did not effect the picture. I plugged the power
supply connector back in and the picture jumped a little bit, but did
nothing more.

I don't know if the voltage errors are a result of some failure in the
convergence power supply, or the convergence module or both. I have a
copy of the "Basic Service Data" First Edition - First Printing dated
1997. This was published long before the historical issues with this
chassis become known, so I have none of the Service Bulletins and
Service Kits later made available.

I've noticed that many of you have extensive experience with this
chassis, and also that many of you have a great passion for your work,
so I'd love to hear your recommendations for repairing this TV.

Thank you,

Andy McClellan

 

[john]

Bad web addy..

kip

 

[Art]

?? Used it today to access thompson's database??

 

[john]

Not the one you gave..

kip

 

[Art]

http://www.thomsonnetwork.com

 

[Art]

Confirmed functional to Thompson Electronics Web Site @ 17:18HRS EDT

 

[john]

That works now ...

kip

 

[john]

This is the first addy you gave....
www.thompsonnetwork.com

Should not have P in it..

kip