And you get no beeps, sounds, or lights flashing?
Try as (like raptor stated) plugging an external monitor and see what that does.
I once had an issue with a user's laptop like this (with a toshetba) and it turned out to be something with the power. I didn't mess with that, but he ended up having someone else mod the power connections on the motherboard (did some type of bridge) and got it working again.
don't know if you have the same issue tho =P