I just built a computer and when I power up the system shuts itself off after about 2 to 3 mins. I have applied heavy thermal paste and the fans are working, so I am not sure what the problem is. The BIOS comes on and when I lowered the power setting, the system shut down again immediately. Most of the parts come from another system that i just replaced and they worked fine on it, i.e the RAM, Video Card, Sound Card. Here are the parts that are new in the failing system:
Rosewill/RP 550-2 Power Supply 550W
Intel Quad Core Kentsfield 2.4Ghz Q6600 CPU
XFX nForce 680i LT SLI Socket 775 Motherboard
Please let me know if any further details are needed.