Samsung PS-50Q97HD Picture Fault

[Easky15]

Hi all, I have here another ps-50q97hd... the initial fault was clicking and the owner said there was some green specks on the screen, The transistors looked fine so i just re-soldered them then tested and the clicking fault was fixed but I dropped a screw and i didn't get it back before testing so when i powered it on it worked fine, then i tilted it back then heard a buzzing sound so quickly unplugged it, a few seconds after there was a bit of a bang... ;-)... Here's a pic of the damage, it's the connector on the x-sustain board from the power board.

http://tinypic.com/r/2ahico/8

Also found a bad 680uf 35v cap and replaced it but still no joy, Heres a video of the fault...

http://tinypic.com/r/24flgfl/8

Thats sound is coming from the power board and it gets worse the brighter the screen is..


Also all boards are securely screwed on while testing..... made that mistake before... ;-)

[tom66]

Re: Samsung PS-50Q97HD Picture Fault

Fuse on X-main OK?

[Easky15]

Re: Samsung PS-50Q97HD Picture Fault

Fuse on X-main OK?

Yeah...

[tom66]

Re: Samsung PS-50Q97HD Picture Fault

Including the small one for 15V?
Have you checked Ve on X-main and -Vsc on Y-main?

[Easky15]

Re: Samsung PS-50Q97HD Picture Fault

VS= 210, sticker says 207, VE= 14.95, sticker says 94??? Where's the 15v fuse?? can't see it to test..

[tom66]

Re: Samsung PS-50Q97HD Picture Fault

15V fuse will be a small fuse near the DC input.

[Easky15]

Re: Samsung PS-50Q97HD Picture Fault

ve = 65.7v, took the reading from the black wire goin to the x sus board from the power board as it looked to say ve on the board instead of using the ve test point on the board, only fuse i see near the dc input on the x sus board is the big white 6.3a one.... also cant see vsc on y main just vs....?? Am I goin blind?? ;-)

[tom66]

Re: Samsung PS-50Q97HD Picture Fault

Might be written as VSCAN.

[Easky15]

Re: Samsung PS-50Q97HD Picture Fault

Would it be vsch??? That's the closest thing I can see to vsc, is there a service manual for this model?

[tom66]

Re: Samsung PS-50Q97HD Picture Fault

Vsch is different. Should measure 140-160v.
I might have a service manual on my site. On mobile right now so can't check.

[satinser]

Re: Samsung PS-50Q97HD Picture Fault

That hissing on your video is coming from one of the transformers either TX801 (va) or TS801(vs). My bet its from TX801. Check with a cardboard tube. Does it hiss from cold or does it start after warm up you could check with ir thermometer. Had one like that recently the hissing only started when top left hand corner reached 35c. Often caused by crack in ferrite or cold solder joints but its unlikely to be the cause of your picture fault.

[Easky15]

Re: Samsung PS-50Q97HD Picture Fault

Yeah satinser the buzzing sound is coming from TX801, Still cant find the test point for Vsc, the only voltage i've found to be off so far is Ve which says on the back of the panel it should be 94 and it only reads 65.6, also isn't it the x main that would cause this type of picture fault anyway so could the low Ve voltage be the problem??

[tom66]

Re: Samsung PS-50Q97HD Picture Fault

It could be part of the fault but not all of it. It should not cause those sparkling pixels for example.