LG 42pt85 plasma TV turns on but has no picture

[freakaftr8]

Re: LG 42pt85 plasma TV turns on but has no picture

Also check RA1 to RA8 for resistance. These are passive. Ive had those go open too. But usually that would not shut the VS down..

[Dannyx]

Re: LG 42pt85 plasma TV turns on but has no picture

Also check RA1 to RA8 for resistance. These are passive. Ive had those go open too. But usually that would not shut the VS down..

What are RA1-8 ? Sorry, don't have the board in front of me right now and my photographic memory's not all that great

[freakaftr8]

Re: LG 42pt85 plasma TV turns on but has no picture

passive 8 pin resistors that carry control board ribbon signals in to the ysus. On the ysus inline with the ribbon input

[Dannyx]

Re: LG 42pt85 plasma TV turns on but has no picture

Those resistors checked ok.

I also get 15v out of these regulators pictured, despite the silk screen on the bottom saying 18v. This happens when I supply 5v to the 5v pin on the main connector. The regulators ARE 15v regulators, so they operate fine.
IPM looks more and more dead at this point.

Also found where -Vy should go (resistor checks OK), but haven't measured it yet.

[freakaftr8]

Re: LG 42pt85 plasma TV turns on but has no picture

The 18v is never 18v in these LGs.. always 15v what I've always encountered. Sounds like your IPM is wasted

[Dannyx]

Re: LG 42pt85 plasma TV turns on but has no picture

I guess there's no point in removing it - there's no "repairing" an IPM from what I gather.

[R_J]

Re: LG 42pt85 plasma TV turns on but has no picture

Well, type IPM Repair into google I have never done this https://www.youtube.com/watch?v=CARdm0o0FyM
https://www.youtube.com/watch?v=UfMOFi7aQN8

[Dannyx]

Re: LG 42pt85 plasma TV turns on but has no picture

Yeah, I remember those. Those are what I watched when I had that first dead IPM I mentioned - transistors are too expensive to justify the effort/risk though, at least locally, since they would probably be relatively inexpensive online somewhere. I wouldn't do this for a client - only if it were my TV and had the time to waste. I think it's getting a new Y sus or going in the bin. I believe the guy said he didn't have bad fuses either, so it could be similar to my case.