It started few months ago. At first they were visible only on some colors in games and they were disappearing when I charged DS. Now they are flickering lines on top screen. They are... something like... red? and they change to green when I start charging DS. I've heard that adjusting resistors under battery could help but I don't have so small screwdriver. Besides I don't think it will help because I've never touch them and some time ago screen was ok. I won't replace screen because I don't know if it's problem with screen/motherboard/ribbon, and anyway I don't know how to replace it. I won't send it for repair because I could just spend little more and buy new DS. Any ideas?