LG 60PA6500 (Plasma) no picture, with sound

[Yomach]

Hey!

I'll start by saying I did some reading in this forum and other places, and I looked into this guide:
https://www.badcaps.net/forum/showthread.php?t=18542
But my case does not match perfectly anything I found.

I inherited a 7 year old Plasma TV with an issue:
After some random time (could be minutes, could be hours), it would turn itself off. I could immediate turn it back on. Most of the times it turned on with no problems, but sometimes it came with no picture (but with sound).
The situation usually fixed it self in a matter of minutes, the picture would come back on.
After about a week of having the TV, it turned itself off, came back with no picture, and it hasn't recovered yet...

I'm attaching pictures of the boards in the back. I will try to turn it on with the top/bottom buffers disconnected to see what's the status, but I would be happy to hear your thoughts!

I'm an electrical engineer with access to, well, everything (Solder, DMM, Scopes, whatever needed).

Thanks
Yoav

[Yomach]

Re: LG 60PA6500 (Plasma) no picture, with sound

Updates:
1. I tried disconnecting the top buffer. But since then, when I try to turn the TV on, it turns itself off a few seconds later. (I hear the relay click).
This happens with both buffers connected, or with just one (any one)...

2. However, If I disconnect the power from the YSUS board (YSUS is the one connected to the buffers, right?) then the TV turns on, and I get only sound.

3. So I guess that the YSUS board is dead, and maybe also the buffers? Any ideas?

4. I wanted to measure voltages on the YSUS power connector, but I think I might have shorted something by mistake, and smoke came out of the logic board :\
Grr...

5. The voltages are:
VS = 206V
VA = 55.3V
5V = 5V

6. EDIT - Surprisingly, the TV still turns on and still has sound! And I get a signal from the tuner/antenna! On the back, the red LED on the main board is working, but the green LED on the logic board isn't.
Is it possible for the TV to work without the logic board? The smoke came out from this chip on the logic board (see picture).

7. So my plan is to buy a new logic board, a new YSUS board, and maybe new buffers?
Any ideas?

8. I can't seem to find a YSUS board anywhere, does anyone have an idea where can I find one? I will also take it off and see If I can find what's the problem and fix it myself.

[thuss]

Re: LG 60PA6500 (Plasma) no picture, with sound

Im not an expert but I think you have blown the tcon board.

But have a look at this it may help


https://www.youtube.com/watch?v=mZh9Lymglrs

[Andrew F. Ali]

Re: LG 60PA6500 (Plasma) no picture, with sound

First of all, PLASMA TVs do not have a T-CON Bd. I think you mean is the LOGIC Bd. Check if you have 5V from the Y-SUS Bd. going to the Logic Bd.

[thuss]

Re: LG 60PA6500 (Plasma) no picture, with sound

First of all, PLASMA TVs do not have a T-CON Bd. I think you mean is the LOGIC Bd. Check if you have 5V from the Y-SUS Bd. going to the Logic Bd.

Bad habit of mine I meant logic board