I have a old MacBook Pro 2012 that shows a white screen with vertical/horizontal lines on startup. I kind of want to make it a project for me to get it back up and running. I saw a video in which they reapplied new thermal paste and some people had success Not sure if anyone has experience with that.
Post some pictures of it if you can. Most likely its a screen bleed. Lcd panels for that model are cheap. lowest i saw was $25. If you're capable of swapping it go that route. It's hardly an issue wit the logic board remember backlighting and such tends to go bad after a few years of use. Check the video with an external monitor. If it's good then you've got a bad LCD panel.
