help with plasma lg 42pc5d no picture but powers on

[mattstolte]

tv turns on just no picture, would it have to be a ysus? I have a hard time figuring out plasmas not sure the best way to figure out what is the problem

[Hamie]

Re: help with plasma lg 42pc5d no picture but powers on

Usually this would be a failed ipm on the y-sus.

Is the fuse open?

Vsc and -vy voltages?
These are Measured across a couple of marked resistors.

[mattstolte]

Re: help with plasma lg 42pc5d no picture but powers on

This is what i gathered so far, well first off tv turns on soon as i plug it in and the buttons will not shut it off and i dont have a remote to try. So makes me thing main fault? No open fuses.
Va 59
vs 192
vz bias 140
-yz 160
i dont know what ysc is or where to check that thanks for your help so far and sorry about the caps. My button got stuck

[Hamie]

Re: help with plasma lg 42pc5d no picture but powers on

Ok connect the 2 holes marked autogen on the control board.

Disconnect the lvds cable that connects this board to the main board.


Power on and see if you get test patterns.

Autogen located here:

[mattstolte]

Re: help with plasma lg 42pc5d no picture but powers on

Ok i got the auto gen and test pictures appeared on screen so does that mean bad main?

[Hamie]

Re: help with plasma lg 42pc5d no picture but powers on

Yes, almost certainly.

[mattstolte]

Re: help with plasma lg 42pc5d no picture but powers on

What's crazy is i had a newer lg plasma i fixed couple months ago kept cutting in and out and when picture would cut out i would still have sound. And I did the auto gen and test patterns appeared and I ordered new main and still did it and what's weird it happen to be the digital main fault

[tom66]

Re: help with plasma lg 42pc5d no picture but powers on

The autogen test bypasses the main board and part of the control board. If the autogen works, the PSU, Z-sus, Y-sustain, panel, buffers etc are all working ok. There is a very small chance the control board LVDS processor is faulty but in almost all cases the main board is the only fault.

[Shane711]

Re: help with plasma lg 42pc5d no picture but powers on

I have this TV LG 42PC5D today and I have the same problem in this post. So I did the autogen test, tried a wire clip first but it would not work so I soldered it in and presto, the TV turns on with the test patterns showing all over the screen, nice nice nice! TV works great so I guess I must have a bad main board. The TV will not turn off either. So I am going to order a used main board and see what happens.

[tvtimmy]

Re: help with plasma lg 42pc5d no picture but powers on

You should be good to go. Dont forget to remove the soldered in jumper.

[Shane711]

Re: help with plasma lg 42pc5d no picture but powers on

OH YEA! I removed the soldered jumper and got the main board from eBay for $20 & free shipping. Hope they send me a good board.

I have at least another 200 TVs to fix. I will try to get them all done by Thanksgiving.