Standard debugging is to open the case and remove parts until the PC starts beeping. First get rid of any USB, firewire, etc. attached devices. No wires from your PC except video to monitor and power to wall socket. Does PC start beeping? Booting? No, bummer. Pull the video card if you have one, what happens. then pull memory, what happens, etc. until all you have is a bare MB, power supply and CPU. All other thing disconnected. At this point you shoudl get beep codes (google beep codes). If not post.