What graphics card(s)?
Any other hard drives? optical Drives?
Your power supply has 4x 18 amp rails. It would be pretty easy to overpower the rating of a single rail, which can cause a variety of malfunctions. I doubt that's what is causing your problem.
Take your CPU out of the case and run it on top of a piece of clean cardboard or other non-conductive surface. If it runs fine, then you know you have a shorting problem, which is a much more likely cause of your problem. When you have the mobo out, look at the bottom to see if there are any abnormally long pins or solder blobs that could be touching below the standoffs.
I put two layers of electrical tape over the standoffs (doesn't have to be pretty, just stretch a strip over and let it stick to the back plate) and use a fiber wafer above the board. I drive the mounting screws through the electrical tape. Do that just to remove one source of problem from the equation.
Inspect the wires on all your fans, particularly any that are connected to the mobo for power (like the CPU fan) and be sure that none of them are damaged.
MSI 790FX-GD70 BIOS v 1.6
Phenom II (Deneb 945 3 GHz)
-Zalman CNPS 9700 NT
2x2GB Corsair Dominator 1600@ 9-9-9-24 1T
Pioneer USB DVD/CD Combo
WD 1.5TB drive to be put in enclosure some day.
Corsair TX750w (single 12v+ @60+ Amps)