Could be a couple of things...
If you don't hear a beep, you're not making past the post. Bad memory can cause this also. If there is more that one stick of ram, remove one and try it.
If you have the same issue, try putting the other one in. If it's still the same, try removing the video card, if it's not built on to the motherboard, and try to start it up. I know you can't see what's happening, but if you hear beeps, it means the video card is bad and was preventing the machine from posting.
Last but not least, remove all the memory and turn it on. (with the video card in if you took it out) If you hear beeps, it's posting and you have 2 sticks of bad memory. If none of that works, your motherboard OR processor OR both is fried and there's really no good way to distinguish which one it could be. :thumbdown: