New build-self pc can only shuts down after 2 seconds after start

Hello. I hope you can help me.
I just recently been building my new PC all by myself, for the first time ever. After assembling all my parts for my PC and plugging everything into my power supply I tried to turn the PC on. However, the PC can only starts for one to two seconds before it shuts down. After this I can only turn it on again after about 10 seconds or more, but it still start for more then two seconds. I have tried unplugging everything and checking all the wires and my BIOS from top to button, and plugging everything into the PC again. Still no results. My new PC have the following parts:

- Motherboard: Gigabyte GA-Z68AP-D3
- CPU: Intel Core i5 I5-2500K 6 MB Quad Core
- Power Supply: XFX Core Edition PRO650W with 650W
- Memory: 2x4GB Corsair Vengeance
- Graphics: MSI N560GTX-TI Twin Frozr II 2GD5/OC with 2GB RAM
- Seagate Barracude 7200 12 1 TB.

I am affraid that the problem might be that my power supply might now be powerfull enough to power all of my PC, or (even worse!) that the motherboard is broken some how. I hope you can help me

You have plenty of power supply, and a good one.

Follow this guide and look particularly at the section on "breadboarding". It is a pain, but a necessary step anyway, because I think your motherboard may be shorting on the case somewhere. Breadboarding will at least eliminate anything else if all goes well. It is also a good idea for future builds before stuffing everything into the case.

http://www.tomshardware.com/forum/ [...] oting-tips