Is something wrong with my board?

I am building a new pc, so far i have bought

Mobo: gigabyte z77x-d3h
Psu: Aerocool strike x m800w
Chassis: cm690II a

I connected 5 fans to test the psu via paper clip. It worked fine
Then I put everything inside the case and when i powered on, it went on a power on/off loop!

Is this normal? There is no cpu yet and no ram! Checked by unplugging everything except front fan and 24 atx power, it powered on and then turned off instantly and thats it...

If i connect both 4 pin 12v and 24 pin, it will do the loop again! Is the mobo doa? Or is it just looking for a cPu? I read posts here but I am still not sure about mixed answers!

I just wanted to test if proper power is flowing on my mobo...

I can power it off thru the pwr button if I press it for 4 seconds.