heretic
Last time I had similar problems it was a faulty motherboard. BUT, in the last 3 years I have seen other 'dead' PC's with the following causes;
- incorrectly seated video card
- faulty motherboard
- fried cpu
- incorrectly positioned jumpers
- wrong BIOS
- motherboard shorting against case
- incompatable/faulty/incorrectly seated RAM
The easiest thing to do is unplug everything you don't need. Only keep the mobo, cpu (+heatsink/fan), ram and video card. See if you can get something on your screen with just that. If that doesn't work, remove one of the ram sticks (try them both seperately). Infact, just last week had a dead PC come to life with nothing more than remove and refit a stick of RAM
I guess this is not really answering your original query (think I answered that already), more trying to get it to work
bug