LG Plasma Model PDP42x2 Y-sys / Buffers

[johandj73]

Hi Guys

Great Forum!

I have a 42" Plasma LG which has no image but sound and thought it will be a nice project to try and repair myself.

Model LG Plasma PDP42x2.

So when I opened the TV I found a blown fuse on the Y sustain board. After doing some research and checking the the board (short on SUS and ground) I came to the conclusion that the board had failed. I bought a replacement used board on ebay and fitted it. The problem remained (no image only sound). I removed the buffer boards but could not find a short. I checked the board but the fuse was intact and no short on the SUS. After trying to find the fault the seller of the board offered that I return the board so they could check it. He informed the that the board is faulty but insists that it was fine when he shipped it.
So now the problem is whether there is another faulty component on the TV that could have damaged the board or was it damaged during shipping etc.

My question is: What could damage the Ysus board. I checked the voltage Va Vs voltages and they are fine.

Any advice would be much appreciated

[ReeceyBurger123]

Re: LG Plasma Model PDP42x2 Y-sys / Buffers

Firstly do you have a DMM ? If yes do you know how to check for S/C or short circuit ?

[johandj73]

Re: LG Plasma Model PDP42x2 Y-sys / Buffers

Firstly do you have a DMM ? If yes do you know how to check for S/C or short circuit ?

Hi

Thanks for responding. Yes I do a have a basic digital multimeter, nothing fancy and I know how to check for shorts.

[awyatt2]

Re: LG Plasma Model PDP42x2 Y-sys / Buffers

upper and lower buffers, I have a Panasonic that had only lower half the upper buffer had failed, nothing was blown the sbgt' s had went open.

[aaronwt6]

Re: LG Plasma Model PDP42x2 Y-sys / Buffers

I thought I would chime in since it was my board that he tried in the TV. The board left after being checked out in working TV here at my shop. After returning, the IPM was blown but not the fuse which is something I've never experienced on this board series. I was trying to assist in troubleshooting up to that point but it put me at a loss as to what could have caused that. Even a failed buffer on these won't usually take out the sustain board, or at least not instantly.

[johandj73]

Re: LG Plasma Model PDP42x2 Y-sys / Buffers

upper and lower buffers, I have a Panasonic that had only lower half the upper buffer had failed, nothing was blown the sbgt' s had went open.

The IPM on the Y sus is blown, and the IPM on the replacement board was also fried. I am worried that another component on the TV are frying the IPMs. It may be that I just bought a faulty replacement board, but I want to be sure before I fit another Y sus board.

I was wondering if a faulty buffer can damage the Ysus board.

[johandj73]

Re: LG Plasma Model PDP42x2 Y-sys / Buffers

I thought I would chime in since it was my board that he tried in the TV. The board left after being checked out in working TV here at my shop. After returning, the IPM was blown but not the fuse which is something I've never experienced on this board series. I was trying to assist in troubleshooting up to that point but it put me at a loss as to what could have caused that. Even a failed buffer on these won't usually take out the sustain board, or at least not instantly.

Thanks! Yea I thought I would try to get some more advice since we are both at a loss. I ordered a new board after receiving your message this morning but I don't want to fit it (once it arrives) before being 100% sure nothing else is causing this.

[aaronwt6]

Re: LG Plasma Model PDP42x2 Y-sys / Buffers

I'll also point out for anyone reading that the shipping box was heavily damaged when it arrived to him. Although I cannot find any parts missing or broken, it's feasible that one could have been damaged and in return caused the IPM to go.