PC not booting

[nikhilmitta]

cpyI just replaced my mobo and along with RAM.
The system will not boot up.

It starts, with the fan running for 15 sec and shuts down. 5 sec later it restarts automatically and the sequence repeats.
The power button on the mobo glows red and there is some sort of a numeric led display on the other end of the mobo which shows 51.

What could be the problem.

I replaced q660 and intel mobo with the 3570k and gigabyte z77x ud3h.

Thank you.

 

[nikhilmitta]

Solved.
The two RAM DIMMs were not placed in their respective slots.

 

[manofchalk]

Look up what the number means in the Mobo manual, and fix whatever issue it applies too. If its something like USB keyboard detected or some other generic error, follow this guide.
http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems