50" LG Plasma poor image

[fusionlore]

I have a dark screen that lightens up after TV has been on for a short time. See pictures. The black will fade as the image changes though slower than the picture does. I replaced three boards 2 weeks ago, I believe they were the z-sus, y-sus and the board they are attached to. Sorry trying to do this quickly during lunch so. Any help would be appreciated.

[rayrod81]

Re: 50" LG Plasma poor image

The symptoms you have described and show in your pictures are usually related to a failed Z-sustain.

[fusionlore]

Re: 50" LG Plasma poor image

Thanks, I replaced the z-sus already and all was fine for a couple weeks so probably got a bad board.

[fusionlore]

Re: 50" LG Plasma poor image

Anyone know where to download pictures that would identify the internals of this tv? I'm not sure which one is the zsus.

[bbjunkie]

Re: 50" LG Plasma poor image

Hi fusionlore - Take a picture with the back off. The guys here will be able to tell you.

Jim

[PlainBill]

Re: 50" LG Plasma poor image

When viewing the TV from behind the Z-sustain is the one on the right.

PalinBill

[tom66]

Re: 50" LG Plasma poor image

Could also be a loose Z-sus power or Z-sus control connector.

[fusionlore]

Re: 50" LG Plasma poor image

Thanks, I will take pictures tonight.

[fusionlore]

Re: 50" LG Plasma poor image

Here is the pic. Arrows point to the 3 boards I replaced. When I got the TV it had sound but no picture. After replacing these it was perfect for 2 weeks then a new problem arose as seen in the photos at the beginning of this post. Thanks for any help.

[pwogaman]

Re: 50" LG Plasma poor image

Those arrows point to the y-sustain and the buffers. The z-sustain is on the other side.

[tom66]

Re: 50" LG Plasma poor image

Replace the Z-sustain. Before you do this, check the fuses, and replace any that are blown; if they blow again or the TV doesn't start, replace the Z-sustain.

[fusionlore]

Re: 50" LG Plasma poor image

Thanks. Both fuses tested good and the unit does power on but the picture is poor as seen above. Does this still indicate the Z-sustain?

[tom66]

Re: 50" LG Plasma poor image

Thanks. Both fuses tested good and the unit does power on but the picture is poor as seen above. Does this still indicate the Z-sustain?

Yes the Z-sustain can also fail open. Try disconnecting the Z-sustain driver FFCs (connectors to panel) - does the picture change? (Do this while off, of course - dangerous voltages present.)