Did you even try to see if it's the Video Card using too much power or not? Take the VC(VideoCard) out and see if it works... Have everything worked b4 you plug that VC in?... BTW, check every connector that connect to each port and see if they are all connected...
Yes the power supply works fine. I had a 8800 gts 512 that fried I guess but everything was working fine in regards of power. The only thing I can think of is the one power connector is not enough since the gpu has 2 power inputs.
Or I'm completely wrong and something else is the problem