System Start-up Problems

Hey guys,

Recently I have been trying to put together the following:

GIGABYTE GA-X58A-UD3R LGA 1366 Intel X58
Intel Core i7-950 Bloomfield 3.06GHz LGA 1366
MSI N460GTX CYCLONE GeForce GTX 460

However, I've encountered a problem and im not sure how to diagnose it. There is no communication with the monitor and when the system first boots, it starts up but immediately shuts down only to restart and appear stable about 5 seconds later. I've tried three different psu's ranging from 650-900 watts and the same thing occurs. I also tried a different video card but still to no avail. Any ideas as to what the problem is? Let me know if you guys need more info about the system.

Thanks much!