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Red Pixels On Screen

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I have an LG 70UN7070PUA, 4k television I'm having a problem with. It's hard to explain but I'm getting these red pixel smears on the screen. They movie around when something on the screen moves. I replaced the TCon board but it's still doing the same thing. It does this on all 3 hdmi ports and no matter what hdmi cables I use. Should I try replacing the main board next, or is something else the problem? Any help would be appreciated.

Update (07/08/26)

Answer this question I have this problem too

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5 Comments:

@zakgraham see if you an post a short video or pictures of what this all looks like

Adding images to an existing question

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I added pics. Forgot to earlier

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@zakgraham this looks like an issue with the panel. Check your LVDS cables that connect to the buffer boards (thin, long circuit boards that connect directly to the LCD). Make sure that those cables are not corroded and that they are properly seated. Let us know what you find out.

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I've checked the LVDS cables and the buffer boards. I uploaded a couple videos of them. They all seemed pretty clean, no corrosion, made sure they were all plugged in right. Still same old red on the screen

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@zakgraham try this. you see those brown plastic ribbon cables that go from the buffer boards to the panel? Those are Cof's (Chip on Film Now find the CoF that corresponds with where you see most of the red discoloration on the screen i.e. 2nd picture where the "gon". You do see that the discoloration is actually a long band from top to bottom with a fixed width. That particular area receives the image control through that particular CoF's. Sometimes the adhesive on the CoF gets' contaminated and can cause this. A bit of pressure on the CoF, right where it connects to the LCD, may change the discoloration. Let me know if this a. makes sense to you and b. if there is a change in the image.

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