Hey I am an IT guy so try these steps.

1. unplug the computer from the wall and wait. Wait like 5 mins. you have to let the charge built up on the board die down. Plug the power back in and try it again.

2. unplug all power to Hard drives, optical drives, everything.... Turn it on and listen for beeps. Let me know what happens.

If you get beeps then plug in your video card and try again to see if the beeps also give a bios error. If they do then you are on to something.

Did you notice any smells or temps of your computer? I know those alienware computers are top knotch but they get the /fail when it comes to negative air flow.