I've seen this happen a few times (and the search feature on the boards seems to be down, so forgivness please if this is a repeat). I picked up a GB at a garage sale and the sides of the screen is being cropped by yellow "lines/bars." Most games can't be played, though simple stuff like Tetris is generally not a problem. You can't see through them or anything, they are entirely solid and only appear when a game is played. You cannot see them when the system is off. Is this fixable?