First build, starts, stops, repeats

[Nismofan]

I just finished my first build. I Power it on and the fans and lights turned on for a second. Then it loses power and stops, a second later it starts and stops again and just repeats this process. This is my first build and I don't even know where to begin to solve this. Anyone know what the problem could be?

 

[dndhatcher]

In the sticky at the top of this forum is a "boot problems" post with about 20 steps for when you have problems like this. Most likely you didnt get one of the power cables plugged in right, or at all.