I picked up an LG 55LN5700-UH that has an issue and I figured I would have a go at trying to repair it.
I've searched here and I have some ideas but didn't really want to hijack any existing threads. Didn't find any of this exact model.
Attached are the model sticker and software version. And the last youtube video link is a short video of this exact set showing the issue.
The set software is up-to-date and the behavior of the screen dimming every 2.5 seconds and then going back to normal and while the slight dimming occurs faint horizontal lines appear. This is much more noticeable in a white screen and/or brighter areas and it also seems more pronounced on the left side of the panel as viewed from the front.
The symptom occurs with the picture reset, all picture enhancing functions turned off and the backlight turned all the way down. Also it occurs with all HDMI ports and different HDMI cables and devices. I can not test the component video connection.
I also tried this but knew it could be too good to be true:
Here's my video of this TV and it's symptoms:
I'm ready to troubleshoot, where should I start?