MSI Z77a-GD55 no post

Hi guys,
I just finished building my new system and when i press start.... i get no post, no beeps.
The phase LED lights stays only on LED1, i dont know what that means, i read the manual and it says something about no reliable power flow to processor.

i tried posting with just the cpu on (i5 3570k) and still i get nothing.

any suggestion on what i can do next?

Thanks in advance all help appreciated.