Samsung 42" Plasma (PS-42Q91HD) - 56K beware

[FearTec]

My brothers 7yo Samsung TV has died with the issues similar to the bad caps issue (sometimes fails to turn on and if it comes on it will turn on again and makes clicking sounds).

I opened the TV and checked for bad caps but nothing out of the ordinary.  It mostly has ceramic caps. 

I will follow the power switch back and see if it is ok (not burnt out) and then trace back to the power board.  it looks like the power button connects near the TV decoder board so maybe the chip is dead.

Q1) Does anyone have a service manual for this TV?


Download: http://simon.fearby.com/temp/eev/marctv/IMG_2022.JPG


Download: http://simon.fearby.com/temp/eev/marctv/IMG_2022.JPG



Download: http://simon.fearby.com/temp/eev/marctv/IMG_2022.JPG



Download: http://simon.fearby.com/temp/eev/marctv/IMG_2022.JPG

[David_AVD]

I have an LG 42PT250 that refuses to start up.  In my case the clicking is a relay on the power supply board.

After some inconclusive searching I changed all the electrolytic caps on the power supply board, but it's still the same.   

Some sources pointed to a fault on the YSUS board(s) causing the power supply to shutdown.  Maybe search online for something along those lines?   

[Bryan]

I enjoy following the videos of NorCal715 on utube. I am sure if you reached out to him he would be able to point you in the right direction as to trouble spots with this particular unit.
https://www.youtube.com/user/norcal715

[janoc]

My brothers 7yo Samsung TV has died with the issues similar to the bad caps issue (sometimes fails to turn on and if it comes on it will turn on again and makes clicking sounds).

I opened the TV and checked for bad caps but nothing out of the ordinary.  It mostly has ceramic caps. 

Make sure that you check the caps using an ESR meter. They don't have to be visibly bulging or leaking to be bad. Capacitance meter doesn't help neither - I have pulled quite a few caps that still have the rated capacity and everything, but sky-high ESR. 

Usually the caps going bust are the low voltage ones at the output of the PSU - that would be the first thing to re-check. The clicking you are hearing could be some sort of safety relay turning the thing off. Sometimes even the coils in the PSU could make such noise alone (had an ATX PSU doing that).

[Rasz]

checked for bad caps

how?

start with voltages
plasmas = sustain boards dying

[janoc]

checked for bad caps

how?

start with voltages
plasmas = sustain boards dying

That and Samsung notorious CapXon (also known as Crap-xon) capacitors in their PSUs. If the TV is using those, change them without even measuring - they reliably die after the 6-7 years.

Dave has a video on how to find bad caps using an ESR meter:
http://www.eevblog.com/2012/10/06/eevblog-365-esr-meter-bad-cap-monitor-repair/