My first boot . . . PC not starting up!

AndyC53

Honorable
Oct 31, 2013
463
0
10,960
Hi community,
I have a REALLY big problem, I have just finished my first PC build and when I power it up, it stays on for two seconds and the fans power up but then it stops and switches off. I dont know what to do. Do I have a faulty component? Did I not build it correctly?