LG 75UJ6470 Black Screen With Sound and Backlight

Sep 25, 2019 6:34AM PDT

We've owned our LG 75UJ6470 a little over a year. Recently the screen periodically starting showing black and white vertical lines. We took it in and the technician replaced the power board, main board, and tconn board. After which it worked for awhile but now it only shows a black screen with some kind of backlight ripple effect that will change when we switch channels. The audio still works fine. Does anyone know what could be causing this? I've uploaded some images for reference.

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That's bad.
Sep 25, 2019 7:29AM PDT

If you assume the replaced parts are good then you replace what hasn't been replaced. Cables and the panel.

This may be a fine example where we need more than one year warranties on the more expensive models.

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From my understanding
Sep 25, 2019 8:51AM PDT

The cables were replaced too. What I don't get is the picture started working again perfectly.

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I can't guess the timeline.
Sep 25, 2019 9:20AM PDT

But repairs have a warranty as well. To me it sounds like you have a warranty situation.

Also, I'm only an electronics designer and more. While you may be asking for "why?" I can't really tell you since most if not all TV makers today do not publish engineering grade documentation for us to dive in and find out why it failed. We are left to the service manual and experience to guide what to replace. This can upset those used to the old days.

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I appreciate the help.
Sep 25, 2019 10:37AM PDT

This would have been a perfect warranty situation. Unfortunately since I am currently working in the Caribbean where I purchased the TV that warranty was voided. Something the retailer "forgot" to mention when I purchased it.

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See me nod about that.
Sep 25, 2019 12:18PM PDT

I've heard such before and a 75 inch set can be expensive.

But the shop that did that repair is now on the hook for the time of their warranty. Back to them.

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