LG 50ps30fd-aa display issue diagnosis required

[Nath78]

Hello everyone.

I have a 50inch LG 50ps30fd-aa that i need some help with.

The unit turns on just fine and displays a picture, sound is also fine.

The picture is of average quality/grainy with moving/snowy pixels more noticable on lighter colours. On some colours there appears to be a purple-ish tinge. On a white background there is a green/blue tinge. When the picture changes on screen there appears to be a temporary burn-in like effect.

Any ideas on what the issue is likely to be?

I have attached some pics..

The first pic should be a plain white screen. You can see the temporary 'burn in' from what was previously on the screen and the obvious green/blue/yellow wash.
The other 2 pics have the purple pixel wash on the white area of the display (its everywhere on screen but easier to notice on the white areas)..

[ReeceyBurger123]

Re: LG 50ps30fd-aa display issue diagnosis required

Have you a DMM ? Looks to me like possible Zsus issue which is common on this chassis. Could also just be age on the panel too.

[Nath78]

Re: LG 50ps30fd-aa display issue diagnosis required

My brother is pretty good with electronics and will have a DMM. Havent brought it to him yet (not easy to lug this thing around).
From googling i was thinking maybe Z-sus but i'm obviously no expert. I can get a new z-sus for about $120 australian dollars (tv cost me $50) but if its possible to fix with replacement capacitors etc that would be a better/cheaper option

[ReeceyBurger123]

Re: LG 50ps30fd-aa display issue diagnosis required

We need to test the Zsus first buddy, theres a test point on the board that says Zbias this should read 98v Dc let me know what that tests ifs thats ok we will then check the panel voltages as it may just be mal-discharge/age on the panel.

[Nath78]

Re: LG 50ps30fd-aa display issue diagnosis required

Alright thanks. I'll try to get it to my brother as soon as I can for testing..

[chrismurphy]

Re: LG 50ps30fd-aa display issue diagnosis required

check zsus for bad joints , next increase ysus voltage slowly by no more that 8 volts and see if it improves , looks like the panel is old