Dell Studio XPS 8100 Died

Hi,

I have a Dell Studio XPS 8100 from late 09, died on me this morning, not quite sure why. Of course its out of warranty.

Running windows 7, GTS 240, 8 Gigs of ram Quad i7, everything stock.

I was thinking the power supply unit died because it wouldn't turn on at all. So I replaced it with this guy

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

It now powers on, but hangs on windows load.

Restarted to boot from windows 7 CD to try to repair disk, but it hangs when the cd loads.

I'm thinking it could be the new power supply unit. My GTX 240 needs one 6 pin pci-e connecter which my new PSU has, but for some reason only 5 out of the 6 pins on the pci-e power cable have have metal connectors which is odd. I looked and only 5 wires are connected to the 6 pin connector, where as the stock Dell psu has all 6 pins.

I tried resetting the Ram, and the battery, maybe a dead battery?

Any help would be much appreciated.

Thanks!