You can find YouTubes showing such on many makes and models. But it doesn't mean it's what they found there. You as a TV tech would use your service manual and prior repairs as your guide to what to replace. If it's the panel you use your best effort not to upset the owner.
I have an older samsung plama (about 5 years old) and its been developing these black lines near the top of the screen over the past few months now
First one is 2 pixels thick, and just a few hours ago there's another one about an inch below it thats only 1 pixels thick
Is there a way to fix this?