My Turn Now...

[McNeo]

Ouch...good luck trying to find a socket 478 motherboard.

Also, it does sound like your motherboard has gone. The exact same thing happened to me, with the same affects you describe.

One thing, when you get a new mobo for your computer, do a stress test on the RAM. When it happened to me, it damaged my RAM and i get massive memory leaks from cold startup. The modules work fine when warmed up though...

Power to the graphics card should be there (all the fans should start spinning like normal) but the power to the CPU and RAM has gone I suspect.