When a power supply fails, it frequently will take out other components. Possibly the motherboard. I had a psu short out and take out both of my hardrives. Everything else was fine.
Unplug the pc and ground yourself by touching the frame of the pc before touching anything inside.
You might get lucky by re-seating the video card and the RAM. See if it boots. If not....
There are different ways to handle this. I think that I would disconect all peripherals except the keyboard. I would remove all cards except the video card. Unplug the machine first. I would re-seat the video card and remove all but one stick of RAM. I would re-seat the RAM stick. Since there is nothing on the screen, I would disconect all of the drives including the hardrive. The bios info will still be displayed on the screen with the hardrive disconected. The first goal is to get the bios to put something on the screen.
edit...I would reseat the video cable on the card also.
Edited by macten, 03 March 2007 - 05:58 PM.