It is probably because something hard hit your ds, or it fell on the floor This causes the game generator to get jammed. It will turn on, but nothing will hapen. Get it repaired or get a new one. P.S.- For future reference, put a hard ds cover on your ds so this wont happen again. But something called the Ds Y is coming out soon, so you can wait until that comes out. It is even newer than the ds or the dsi.