My computer turns on for one second then turns off again

[Hellfire57]

hi i just built my new gaming pc and when i turn it on the fans run for a second and then turn off
i have a b500w psu from coolermaster anyone know how to fix

 

[IRyannHD]

What are your full specs?

 

[boosted1g]

Check all cable connections, make sure ram, gpu and all cards are properly in their sockets.

You are sure you matched the cpu up properly with the arrows?

 

[IRyannHD]

Also do you get any post beeps?