LG 50PA5500 No Audio Issue - Partial static video

[Shorteous]

Back story:

I have a LG TV initially had no video but had clear audio. Did some trouble shooting and narrowed the issue down to a bad YSUS board and bad upper YBuff Top.

Further Isolated the top most IC as having a short between input voltage and a few of the "header lines".

Replaced all three boards: YSUS and Upper/Lower Ybuffers.

Upon Turning the TV back on, the screen flashes and now there is only a snow like image on the bottom bar. All other bars are black.

Continued Trouble Shooting:
Removed the top buffer board, Checked for shorts between V/datalines there was no shorts. Powered on TV with no top buffer and there was no change, only the bottom most bar had any image. (Audio still fine).

Checked VSC, it was fine at 150V.
Checked VY, it was fine at 190V
Checked ZRB, it was fine at 150V

Control board gives a Long - Short - Long - Short status indication.

What are the next steps for trouble shooting? It looks as if the YSustain and Buffers are fine and atleast the voltage in the ZSustain looks to be fine. I was worried about a possible tear in the top YBuff ribbon but I did not see any and the board seems to have survived multiple power cycles since replacing them.

[dick_barton]

Re: LG 50PA5500 No Audio Issue - Partial static video

Have you a picture of the screen?

[ReeceyBurger123]

Re: LG 50PA5500 No Audio Issue - Partial static video

Have you a picture of the screen?

Plus boards.

[Shorteous]

Re: LG 50PA5500 No Audio Issue - Partial static video

i'll take pictures tonight and upload them

[Shorteous]

Re: LG 50PA5500 No Audio Issue - Partial static video

So on the control board, the IC gets rather hot quickly. It's not burning hot but it's much hotter than I would expect - especially since it is not driving any images currently. None the less, the should just be toggling DIO anyways as it shouldn't be driven anything directly.

So I'm assuming the control board is also bad, but is there any other components down stream of the control board that could have been affected as well?

It looks like the YSUS, YBuffs, ZSUS, and ZBuffs are all ok, the power board seems to be fine as well.

[Shorteous]

Re: LG 50PA5500 No Audio Issue - Partial static video

Also, the new top buff board is not installed because I removed it to see if the screen image would change (show half an image) and I also wanted to test the IC's to make sure that an IC did not blow again. The board tested fine and the image was changed in anyway. I just need to reinstall it at some point.