Well, the speaker is your best friend for boot problems. Now we don't even know if you're getting past the POST. Hrm... do you have 1 or 2 sticks of RAM?

If you've got 2 sticks, then pull the left one out. Boot up. Did it work?
Put the left one back in. Pull the right one out. Boot up. Did it work?

If neither of those worked, or if you only have one stick of RAM, I'm still going to go with bios. If you don't have a picture (and can't get one through any video cards that I'm going to assume you haven't tried yet) then you're going to have to hard reset the bios.

I'm going to need you to find out what motherboard you have. Basically the same will not work. Get in there and get a model number or something. There should be a few strings of numbers and letters on your motherboard. Just write down a couple and Google them. I'll do it for you if I must...

Anyhow, at that point, we can get a manual online and go ahead and set it back to onboard video. *crosses fingers* Hopefully, that'll fix your problem.

What is it they say about silence being golden?