Strange problems

Every time I turn my computer on it starts up but the screens black and there is no beep. I push restart and it loads up fine. I used to have a faulty graphic card and that would beep twice and stay black. This is different. Anybody know what the problem is?

Do any fans spin up? If they do, you may not have a good enough and/or large enough power supply.

Right after I posted that last post it all started up fine. Afterwards no problems.