New PC has problems starting

Hello

Today I bought a new system
Only problem it didn't do anything once assembled
I checked everything 10 times nothing, then after holding the power button down for a while 30-60sec all of a sudden the system boots up.
Coming into the BIOS I see all my components are well (fiew though I wrecked something). Only problem now is, what's wrong?
Reset button works once it is started. If I push on the power again, then it stops. If I push again on the power, nothing   (have to wait and then it starts)

I thought it was the PSU but I have 620W ?? Isn't that enough.
Please please help  

Here are the components I bought:
Intel Core i7-3770K, s1155
Asus P8Z77-M PRO,socket 1155
EVGA GeForce GTX680,4GB
Western Digital Red 1TB - 3.5inch
Corsair Vengeance DDR3,1600-8GB
Cooler Master Silent Pro M2 620WATT
Cooler Master CM 690 II Advanced
LG DVR DL 24X,SATA