samsung un65nu6900f common problem, digging deeper

[Cornito]

I'll do the same, but now I may have a chance to keep it alive for some times.

I've redone all solders with better tin, smaller wires and I've added the dcdc step up.

It works, this has a bit corrected the red color. But now I have a small black line at the middle of the screen some times.

Please find attached the pictures of the job and a short video where we can see line appearing .

[Cornito]

I've corrected my line that appeared some times by increasing a bit the VGH voltage, from 18.3 to 19V.
still having a red color issue on one side, red is more pink than red.

[lotas]

You won't be able to do it perfectly, since the CKVs on the non-working side don't work, try restoring them, maybe the problem was only in the VGH.

[Cornito]

I've reduced the VGH voltage, to protect the panel only, the issue was on CKV.
The only thing that I could do I to check which one is the defective one. And rebuilding the others may help.
But I'm not sure that this will help the panel to stay alive for long time

[lotas]

Well, at least that's what it's like. You can also try...

[Cornito]

Back on this topic to update.
tv lasted 2 months and then back to black screen.
I'll check in couple weeks if there is something wrong on DC to DC or of the second side of the panel is shorted now

[retrorepair2]

This TV was working ok after taping it for about 6 months but started doing the boot loop again so I removed the tape and tried this out which worked but now get the attached.

Tried re-adding the tape (literally just blocked all control lines to the right side of the panel) but then get a completely blank screen.

Bit bummed out, is the panel just toast now? I've reseated the ribbons but same thing.

[Cornito]

You can't block clock signals on both sides otherwise you'll get vertical lines or black screen.
if both sides are defective now, there is no solution.

[retrorepair2]

I've only blocked the right side clocks etc but then I get a blank screen. If I block none I get the result in the picture. This is with the VGH taped on the LVDS cable (there's no resistor on that board) and the signal jumped to the panel PCB test point as in the original post. In this case, anywhere from 1k to 100k works but I think the panel must have just now died

[Cornito]

Did you retest from the beginning, with the jumper between the 2 test points with only one side connected, to check if there still a side which is working normally.
On TV i've saved (dead since, i'll need to confirm that the panel is definitely dead or not) first i've removed the limiter resistance on non working side,
Then I cut the VSS line, Then CKV lines that enter to the panel one by one, trying to make the cut reversible.
The cut to VGH to supply the line entering in the panel with the 14v coming from a capacitor next to the cutted line.

Regards

[retrorepair2]

This TV only has one LVDS cable, you can separate the sides on the filter board but it won't then turn on at all.

This is a UE70AU7100KXXU. Confirmed before doing it there was no voltage on the VGH test point on the main board and now there is but it looks like this

[Cornito]

So this confirm the fact that it's on the main driver that you've got the issue.
I had the same case, I cutted the VSS line on this driver, that permitted to get an image, that was not good, I needed to cut CKV lines and link them to the ground to be able to get a not so bad picture quality.

[Cornito]

You can check pictures i've posted on # 101
https://www.badcaps.net/forum/troubl...89#post3205489

Regards

[retrorepair2]

Didn't it die anyway? I may just let someone else have a go, seems like a lot of work for no real reward

[Storyteller12]

This is a cheap TV with a known screen defect.
Not worth all the trouble to be honest. I appreciate the dedication to trying to find a solution but sometimes things just belong in the trash. This tv being one of them.
Between the bad screens, the backlights burning out and melting diffusers.

[Cornito]

you right, it's not a good TV, but anyway we spent money and that shit and if we can save some time before having to buy another one it could be great, this will reduce our wastes.

I'll try to fix what can be fixed, and if there is nothing really acceptable, i'll resign to put this in trash.

Samsung should be under class action for that mess