Samsung plasma DEAD......

[grabcol01]

Hi all, Well what a great web site, just hope of some help!!!
anyway in my drunken state one night I said yes I can fix a donated 50" samsung plasma tv, the standby blue light come on for a split second and then goes out, no other signs of life either, NO clicking of relays, also don't have 5 volts or 12 volts coming from psu pcb. Fuses all o.k, I know the t.v was in storage in a shed for 18 months...... should I get a repair kit from ebay or something else..?????

[Alastair E]

Re: Samsung plasma DEAD......

Model-number and pictures of its internals would be a good start!

[grabcol01]

Re: Samsung plasma DEAD......

Sorry,
Model. PS-50C96HD
MODEL CODE. PS50C96HDX/XEU
TYPE NO. CA50C9
50 HZ, 480 WATT
MANUFACTURE. SEPTEMBER 2007.
S/N. Z5993SSP900124W.

[grabcol01]

Re: Samsung plasma DEAD......

5 heatsinks, 3 transformers, No obvious knackered caps or dry joints..

[grabcol01]

Re: Samsung plasma DEAD......

Also, does anyone know if Samsung are still honoring the known cap replacement scheme up to build 2008.... ??!! on the psu pcb...

[Alastair E]

Re: Samsung plasma DEAD......

Pictures of Y-SUS/PSU and X-SUS?

[grabcol01]

Re: Samsung plasma DEAD......

I'm reasonably confident that X & Y sus are ok. deffo no 5 or 12 volt from psu, no clicking... is it worth just changing all electrolitic caps.... I will post pic of psu tomorrow... Thanks for your input Alistair & I know its hard with out a pic to have a ref of what i have ... cheers

[Alastair E]

Re: Samsung plasma DEAD......

Googling model-number has illustrated the chassis you have....

Got one of those abortions in the garage!

Randomly changing caps I suspect wont do a lot to be honest, No 5V--at all, as in No STBY 5V....?
--Only cap worth changing I would think--would be that associated with the STBY 5V from the STBY supply reg....

[grabcol01]

Re: Samsung plasma DEAD......

Do you have a pcb ref..., there is 5 volt on a test pin on pcb, but nothing at any connectors, what do you think about no 12 volts either ?!!

[Alastair E]

Re: Samsung plasma DEAD......

The 12V may only activate when the set is fully on--not sure on that, but wouldnt at the moment be too concerned about that.

The complete lack of a 5V at any output pin of the PSU is the main issue I think.....
--Trace back from the mainboard--the pins should be marked on that board....

[R_J]

Re: Samsung plasma DEAD......

I just repaired a set simular to this, there was a shorted 30volt zener in the standby circuit near the 8 pin standby ic. Also the standby cap was bad
But your set might have a different board.

[grabcol01]

Re: Samsung plasma DEAD......

Here it is, the offending beast!!

[grabcol01]

Re: Samsung plasma DEAD......

R.J, what was the diode exactly, do you recall. Its the same board lay out !!!

[Alastair E]

Re: Samsung plasma DEAD......

Hmm--That looks to have had a hard life....

--Maybe on most of the day--everyday in an over centrally-heated house, by the looks of the board discolouration!

The plugs are marked. Check the STBY 5V at the double-row socket bottom left of the board.

[grabcol01]

Re: Samsung plasma DEAD......

No voltage present, do you know what diode zd8803 is spec wise or is there a schematic that i can look at on the web site as a pdf type thing......, I.m going to replace al caps as they are well know for a bad manufacture used by samsung.....

[anotherdude]

Re: Samsung plasma DEAD......

No voltage present, do you know what diode zd8803 is spec wise or is there a schematic that i can look at on the web site as a pdf type thing......, I.m going to replace al caps as they are well know for a bad manufacture used by samsung.....

i'd say you're just wasting time and money doing that, unless they are visually bad

[Alastair E]

Re: Samsung plasma DEAD......

Aye--Replacing all the caps on spec is pointless--Unless you can confirm they are bad, and probably cost more than a working supply!

Only ones worth doing are the two or three associated with the STBY 5v supply, as they are cheap enough--and always 'on'
--To replace much more is a waste of effort and money at this stage.

[grabcol01]

Re: Samsung plasma DEAD......

There is a GOD...... I've just had a final look before taking to tip tomorrow and like you said Graham as I have read on other sites, shorted out PS-ON & rtn pin next door and 2 quick clicks from relays, then a click as short released..... plugged all the leads back in to p.s.u.............. shove the mains lead in and click click and T.V is on.... all the menus work and no unusual looking lines or anything, just need to get a aerial lead up its back side and hopefully its a good one........ Maybe the relays just needed a good short....

[cossiesmit]

Re: Samsung plasma DEAD......

Hi grobcol01, have sent you a PM/email asking for help.

If you could reply that would be brilliant. Cheers, Mark.

[cossiesmit]

Re: Samsung plasma DEAD......

No Need, found a dry joint next to the PS-ON and heated it up and bingo!