RCA P52753AT Big Screen TV Power Supply...

[jsandlin]

I got a big screen tv from a family member. They said that it would
work but it would lose color and go to black and white sometimes. I
plugged it in when i got it home and the power light came on and
blinked a couple of times, then went out. I then tried it again and the
same thing happened. It done this about 5 times before it stopped and i
smelled that familiar electronic burning smell.

I opened the back up and could see that a resistor was burnt on the
right side board, but that can't be the main problem. I can hear a
clicking sound on the power supply board when i plug the power cable
in. It only happens for a few seconds and then quits until i unplug the
power cord, wait a minute or so, and plug it back in. Is this a rely
clicking like that?

Please help. I would like to get this going.

Thanks
Jason

 

[Homer J Simpson]

I opened the back up and could see that a resistor was burnt on the
right side board, but that can't be the main problem. I can hear a
clicking sound on the power supply board when i plug the power cable
in. It only happens for a few seconds and then quits until i unplug the
power cord, wait a minute or so, and plug it back in. Is this a rely
clicking like that?

Probably the SMPS cycling against a short.

 

[jsandlin]

Is there a part number that i can look for? What does the SMPS look
like?


THanks
Jason

 

[Homer J Simpson]

Is there a part number that i can look for? What does the SMPS look
like?

If it's a short replacing the SMPS won't help.

 

[Dave]

Is there a part number that i can look for? What does the SMPS look
like?

SMPS stands for switch-mode power supply. It's not a component or board,
it's a series of components on the main pcb. TV's contain protection
circuits which detect incorrect current and/or voltage situations at various
points in the TV circuitry. What's likely happening is:

1. You turn the TV on
2. The logic portion of the TV (low voltage) closes the main AC relay which
powers up the flyback and rest of the circuits (high voltage).
3. One of the protection devices senses an out-of-spec condition and sends
a message back to the microprocess.
4. The multiprocessor shuts down the set.

Truly I mean no offense here, but the likelihood of your being able to fix
this set yourself with the skill level you exhibit in your postings is
incredibly small.

SMPS power supplies and the HV portion of your TV set have voltages that can
kill you (think 30,000V). There are charges built up in various capacitive
components which can hurt you badly even if the set is not plugged in.

Take it to a qualified repair shop.

Just my 2 cents.

Dave

 

[David Naylor]

I got a big screen tv from a family member. They said that it would
work but it would lose color and go to black and white sometimes. I
plugged it in when i got it home and the power light came on and
blinked a couple of times, then went out. I then tried it again and the
same thing happened. It done this about 5 times before it stopped and i
smelled that familiar electronic burning smell.

I opened the back up and could see that a resistor was burnt on the
right side board, but that can't be the main problem. I can hear a
clicking sound on the power supply board when i plug the power cable
in. It only happens for a few seconds and then quits until i unplug the
power cord, wait a minute or so, and plug it back in. Is this a rely
clicking like that?

Please help. I would like to get this going.

Thanks
Jason

Ohhhhhhhhhhhh this is a common problem on that vintage tv, Those in
the know will know what I mean you have a convergance amp failure
proberbly several of the con amp tranistor on the con amp board are
shorted, burn't a couple of resistors.. this is what is shutting down
your set. take it from the pros like us and take it to a good shop. the
light box come right of that set just bring that , and be prepared to
shovel out some large somes of cash projo's are not cheap to fix

 

[tem00]

I have the same unit. Mine was the main power supply (SMPS) with a
blown HOT (horizontal output transistor,) shorted HV Splitter (the
thing behind in the front panel that has all the big red wires going to
it,) and some bad caps in the SMPS that were causing the voltage to
ride too high in the first place.

I bought the repair kit from http://www.tritronicsinc.com and got it
going. Unfortunately, I messed up the convergence and it is a real
pain to readjust and I gave up on it for a while. I'm spoiled by the
newer sets where you do it from the remote in service mode.

Sounds like you have other problems to boot and I don't know about
those factors. You can
buy a service manual and try and track the problem down but the time
may not be worth it.

Good Luck