LG 43UK6200PLA - yellowish picture

[tomislav4545]

Hi everyone. I have LG 43UK6200PLA which stopped showing picture a while ago. The main board is model EAX67872805. It has sound and backlight. I tested the two ribbon cables on the tcon board and concluded that one of them is faulty. I taped pins 1-12 and now the picture is there and there are no glitchy lines. The problem is it switches from normal color to yellowish color repeatedly. In the attached photos the first one is normal color and the second one is changed color. Any suggestion is welcome.

Thank you all.

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

maybe try unblocking one line at a time like go to 11 etc: https://www.youtube.com/watch?v=pfrRhw7-ZII

[tomislav4545]

Re: LG 43UK6200PLA - yellowish picture

I did that and it looks like pin 9 is the general problem. When I block only pin 9 the colors are fine but there are pruple vertical lines when screen is black and normal lines when there is picture. Also there is one black line that doesnt change.

[alfatv]

Re: LG 43UK6200PLA - yellowish picture

I tested the two ribbon cables on the tcon board and concluded that one of them is faulty.

Thank you all.

If cable is faulty, you need to replace it

[tomislav4545]

Re: LG 43UK6200PLA - yellowish picture

If cable is faulty, you need to replace it

My bad, I worded that a bit badly. I meant that when I connect one cable only I get half screen normal white and when I connect only second cable it doesn't work correctly. The cables themself are ok.

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

maybe play with it, like block 1-9, 2-9, 3-9 etc.

[tomislav4545]

Re: LG 43UK6200PLA - yellowish picture

After blocking pins 9 and 11 I get a normal picture without lines, but there is slight flickering. Also I noticed if I block pin 12 (along side 9 and 11) the colors change between normal and yellowish like at the beginning. Other pins don't seem to have any effect on colors or flickering. I have no idea what to do now.

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

I wonder if the flickering might be a separate backlight issue?

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

did it flicker when you did the half screen test?

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

something to try, go into settings and turn off all energy saving settings/modes.

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

also for testing have nothing plugged into it like hdmi cables etc. see if it still flickers, some lgs have picture test, something like settings-support-screen diagnose.

[tomislav4545]

Re: LG 43UK6200PLA - yellowish picture

When I did the half screen test it did flicker on the faulty side. Energy saving was on and when I switched it off it only brightened the screen a bit and nothing else. It was tested without any cables just power.

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

.

[tomislav4545]

Re: LG 43UK6200PLA - yellowish picture

I found this video: https://www.youtube.com/watch?v=ESGYMioW4yQ
Does anyone have any idea what is he doing? I watched it a few times but don't understand what does he check when probing left and right side at the same time. Also what should the voltages be at those resistors?

[Davi.p]

Re: LG 43UK6200PLA - yellowish picture

A very slight flickering it's normal in these faults with tape method, you must accept it, the screen is not fully repairable, maybe the best method is drilling method but i haven't fully tested until now.

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

maybe turn the backlights and or brightness down to try to get rid of the flicker, maybe even turn those up a little to see if it lessens but down would be better if it would work.

[tomislav4545]

Re: LG 43UK6200PLA - yellowish picture

A very slight flickering it's normal in these faults with tape method, you must accept it, the screen is not fully repairable, maybe the best method is drilling method but i haven't fully tested until now.

What is the drilling method? I am probably going to leave it as is for now. It is watchable and if you don't look for flickering it's not that noticeable.

[tomislav4545]

Re: LG 43UK6200PLA - yellowish picture

maybe turn the backlights and or brightness down to try to get rid of the flicker, maybe even turn those up a little to see if it lessens but down would be better if it would work.

Changing the brightness didn't do anything.

[Davi.p]

Re: LG 43UK6200PLA - yellowish picture

sorry that method is not tested , i will explain it when it will be

[nomoresonys]

Re: LG 43UK6200PLA - yellowish picture

this one fixed it with tape, thought I still saw a slight flicker over the whole screen tho, unless it's just the video effect of the camera: https://www.youtube.com/watch?v=Gau7xTgtWpo