LG 50PA4500 plasma thin black vertical lines

[Shifty]

A friend dropped her one year old tv off on my workbench, I've never diagnosed a plasma before and it seems like I'm the first to tear down this model.
Dark or shined stuff appears green while bright and whites appear pink, there're evenly spaced thin black vertical lines, every second line is less pronounced. I'll let my picture explain the rest, please help!

[tom66]

Re: LG 50PA4500 plasma thin black vertical lines

Apparently usually just a loose LVDS cable between main board and control board on these models, at least that applies to 42".

[Shifty]

Re: LG 50PA4500 plasma thin black vertical lines

Thanks for the tip, simply removing that cable and replacing it changed nothing. I will get some cleaner and start checking all connections. If anyone has another idea I'll be here working, your input is valued.

[tom66]

Re: LG 50PA4500 plasma thin black vertical lines

Can you post a picture of the control board? It's a green board, about in the middle, connecting to the main input board and the sustain boards, among others.

[Shifty]

Re: LG 50PA4500 plasma thin black vertical lines

here it is

[tom66]

Re: LG 50PA4500 plasma thin black vertical lines

OK, do you see the two holes in the board, and just below, a marking "EXT_AUTO_GEN"? Place a wire jumper between the holes, and unplug the LVDS cable. You should get test patterns on the display when the TV is powered up.

[Shifty]

Re: LG 50PA4500 plasma thin black vertical lines

okay i did that, got some patterns going now.

[tom66]

Re: LG 50PA4500 plasma thin black vertical lines

Are the patterns clear or distorted?

[Shifty]

Re: LG 50PA4500 plasma thin black vertical lines

the thin black vertical lines are present through the test patterns, I'm not sure of what they're suppose to look like.

The first two moving patterns are definitely distorted.

[Shifty]

Re: LG 50PA4500 plasma thin black vertical lines

https://www.youtube.com/watch?v=LCnfkr3TlOw

here's a tube of the test screens

the only one that looks close to normal is the descending horizontal white bar

[tom66]

Re: LG 50PA4500 plasma thin black vertical lines

This confirms the control/logic board is bad.
Should look like:
http://www.youtube.com/watch?v=xgrvRc2JVVQ

[Shifty]

Re: LG 50PA4500 plasma thin black vertical lines

Is there any chance that flashing the board will correct the problem?

[tom66]

Re: LG 50PA4500 plasma thin black vertical lines

Well, you can try it, but I see these boards as being available from as little as $12:
http://www.ebay.com/sch/i.html?_trks...at=0&_from=R40

So I'd just put $12 in it and try it.

[Shifty]

Re: LG 50PA4500 plasma thin black vertical lines

Thanks a bunch,
It's was $40 shipped from USA, I could have got it from a less reputable seller, I didn't need to expedite the international shipping or get the 180 day warranty but it's for a friend. I'll update this thread when I have some results!

[sspoonmann]

Re: LG 50PA4500 plasma thin black vertical lines

well did it solve it?