Sorry if this is the wrong place. I have an LCD TV that got a strange single few inch line of light burn in randomly a few years ago. The thing is, the burn in has…migrated? It’s like a good foot and a half lower than where it originally burned in. And it’s changed angle. There’s a small darker spot where it used to be, even. What’s going on? If I give my tv another 10 years will the burn in migrate off screen like it seems to be doing?
Flooded screen with white, looks like this. Top darker spot is where it was at first. 
See the edit to my comment. If not sharp, could be warping of films in backlight.
Initial burn in was sharp. Looked like someone took a knife to the screen in one spot essentially. But now it’s migrated down the initial spot is just slightly darker than the surroundings, and the burn in is now at a 75⁰ angle as opposed to a flat 90.
Edit I should add it’s not very noticable unless the screen is flooded with white, extremely noticeable, or you know that it’s there.
Sounds to me like the backlight behind the LCD. They have components which could potentially sag, stick, or warp. White screen is probably best way to see. Also look at various angles. May be more visible at some angles then others.
Hard to unsee. I know this feeling. I used to work in the industry years ago. Displays are never perfect and hard to unsee things once you see them especially when it was part of your job.
I mean I’ve gotten used to it by now, it’s less of a bother and more of a mystery lol. I just uploaded a picture of it, if that might help?
Backlight I think. Probably film pack warp / buckle / wetout. Just a guess.
Edit: Worst part looks kind of like a wrinkle.
That shit can MOVE though?
There are various designs of backlights. They typically have a stack of loose components in an assembly. By loose I mean not totally fixed but not too free. They have to free float enought that temperature changes do not cause issues. They also have to not stick, warp, or buckle over time. Harder to engineer then you might think.
So consider what might happen if for example the top backlight film might buckle some then stick to the back of the lcd. The film might deform which would change its optical properties. Then later thermal cycling might cause release. It might do same elsewhere.
Not saying this is mechanism, but just example.
Edit: Keep in mind the LCD is glass, and the backlight components are plastic. Very different thermal expansion coefficients. Then add LED or CCFL lighting and you have a big changing heat source. Add on top of that humidity changes too.
Ahhh okay. Sorta get it. So basically the paper got crunched somehow and didn’t totally uncrunch. And it’s sorta slipping down and that’s why the spot moved…? Well thank you for the help and input all the same lol, the mystery has been bugging me.
Yes good analogy. Just my guess. Been a long time since I actually worked in the field.