I've got a DSi from a friend some years ago that is perfect except for the corners of the top screen. They're darker than the rest of the screen. The pixels can't be dead or stuck since I still can see what's running on these spots while gaming. I want to know what might be the problem and if I can solve it without repacing the screen (I have a New 3DS XL and it's not like the screen corners are completely dead, so it wouldn't be worth for me spending money to fix this). Thanks for helping!