LG 50PT350-UD Abnormal Picture

[crdz66]

Hello Everyone.

I have a LG Plasma Tv with a lot distorsion on the image.
Recently I change for brand new main board and after couple minutes working fine, the problem is back.

Check the pics.

Any opinion can be greatful.
Thanks

[tom66]

Re: LG 50PT350-UD Abnormal Picture

Can you post a picture of your control (CTRL) board. This is in the centre of the TV and generally connects to all of the other boards in the TV set. It connects to the main A/V board, which is the board with the video inputs on it.

[crdz66]

Re: LG 50PT350-UD Abnormal Picture

ok. I will

[tom66]

Re: LG 50PT350-UD Abnormal Picture

OK just right of text IC103, under the rectangular chip, there are two holes.
Get a piece of wire, short the holes together, make sure it is firmly connected. (Do this with power unplugged.)
Disconnect the connector on the right of the control board, it's held down with tape. You can unplug it either at the main board or on the control board, whichever is easiest.
Plug the TV in, and if necessary take it out of standby.

You should see these test patterns, or very similar:
https://www.youtube.com/watch?v=9Lcq...k&noredirect=1

Let it run for some time. Check if the patterns distort, or if they remain stable.

When you go to turn the TV off, in auto test pattern mode first put the TV into standby using the remote/buttons before unplugging it.

[crdz66]

Re: LG 50PT350-UD Abnormal Picture

question.
How can I put into or out standby using the remote?

I check couple thinks on control board.
There are two regulators and show 3.29v and 1.19v
The Led is blink some time not steady. (good or not?)
The connector to y-sustain board show values too low
like:
connector actual value.
23 (15v) 2.74v
25 (15v) 1.12v
27 (5v) 0.22v

[tom66]

Re: LG 50PT350-UD Abnormal Picture

Just turn the TV on or off using the ordinary power button on the user remote.

[crdz66]

Re: LG 50PT350-UD Abnormal Picture

what can I expect?
if the patterns distort?
if they remain stable?
thanks

Just on black/white show distorsion.
vertical and horizontal patterns.

[tom66]

Re: LG 50PT350-UD Abnormal Picture

If they distort = Ctrl board or possibly a sustain board (v. unlikely)
If they do not = Main board (you may have gotten a bad one) or LVDS cable issue

[crdz66]

Re: LG 50PT350-UD Abnormal Picture

Picture from Y-Sustain Board

[tom66]

Re: LG 50PT350-UD Abnormal Picture

So you are saying the moving patterns have distortion on them? In which case, replace the control board.

[crdz66]

Re: LG 50PT350-UD Abnormal Picture

Thanks Tom