Still can't clean it off

[Azula]

So a few days ago I made a post similar to this and I got the the plastic polisher but it did nothing, and I think it's because the burn marks might be between the acrylic or something like that. So what should I try next? *Also this is the still the old picture I didn't take a new one since it looks the same 

[jaslion]

If acrylicbburned the only way to get it off is to sand it down and polish it which often results in frosted acrylic

[Needfuldoer]

If the acrylic burned and melted because the LEDs got too hot, there's not much you can do about it. I've seen that happen to the backlight diffuser panels on edge-lit LCD TVs before. You can sand it back and make it look a little bit better, but it's never going to be perfect again.

 

If you want it perfect, you'll have to get another piece of plastic and cut it to fit.

[OhioYJ]

Acrylic, Lexan, lots of types of clear plastic are sold at hardware stores. If you find a "real" aquarium / fish store, they'll usually have acrylic on hand that they have the ability to custom cut. Many glass shops can do this too. Some hardware stores will cut it for you as well, but depending on how they cut it their cuts may not be as neat. You're likely best bet is to cut it yourself though if you have the ability just so you can get it just right, then install it back in the panel.