Starnge Horizontal Colorful lines on Display

This looks to me like a phenomenon often referred to as “Dust Gate” Some of the data lines for the display that run through the flex cables are severed. This is often the result of tiny flex of debris that work their way into the cables since fans exhaust into this area to the front of the display. And it is just a general magnet for crumbs. As the lid opens and closes these little bits often get caught, progressively working their way through the cables.

This kind of damage can be really difficult to see. It’s typically on the under sides of the cables and the pockmarks causing damage are best seen under a microscope.

That can be repaired, but it’s tedious at best and requires microsoldering skills to resolve. Your best bet here is likely to replace the display,