Dell Inspiron 6000 won't start up, screen stays black

My Dell inspiron 6000 laptop stopped working. It shut off while I was online and when I try to restart it, it goes to the start up screen (black, says dell in blue letters) then the whole screen goes black and stays that way. I left for an hour and came back and the screen was still black. I have held the power button down until it restarts and that didn't work, I have pressed ctrl+alt+del and that didn't do anything either. I have also run a diagnostics test and everything passed. I have run out of things to try. Can anyone help me?