Bought a new agp vid card to replace my dying A-I-W 9800, it's a EVGA 256-A8-N542-T2 Geforce 7600gs 256mb. Before I install it I'm wondering now if my power supply is too small for this card. It looks to be a no name "POWERUP LC-B400ATX"
Here's what it says on the sticker of the PS, hope it helps.
Yeah I had the same problem, I had only a single +12v rail as you, and that was trying to power everything with mobo/all the case fans and other things in found in there + the power consuming 88000 GTS.
Basically this produced rails to drop amps down causing the whole system to crash while playing.
But then again it depends on what other parts you have in the setup as well. Check out this one: