Newly Built Computer Turns On and Off repeatedly

[KegGuy]

Hey guys, i recently bought a new desktop and had it assembled at a local computer store. It has stayed on my desk for a little over a week, untouched except for the few seconds i removed the display window and reattached it.

After connecting both the new monitor and keyboard to the tower and turning it on, within two seconds it would shutdown, only to tun itself back on again and turn off once more. This process repeated until I isolated the power.

I was really hoping that this could be easily fixed by myself as it is on Christmas and would be a while before any 'professional' help can be sought. Researching online i narrowed down some possible issues/causes:
1. Faulty power supply
2. Issue with how the motherboard was installed
3. Heatsink fan not attached correctly to eithet PSU or CPU

I was wondering if anyone here would be able to determine what may be the cause and if it is only a faulty connection of the fan how i could fix it?

Any other information is most welcome! Thanks in advanced and Merry Christmas!

P.S. here are the specs for anyone wondering (the PSU however is a CoolerMaster GX II model)
http://pcpartpicker.com/user/KegGuy/saved/3es5

 

[smorizio]

start with the easy stuff. open the case with the power off. look to see that both your ram dimms are seated. if not put them back in till the clips lock. look at the cpu/cpu heat sink if the pc was shipped or moved with a large heat sink the cpu may have walked out of the slot. if your handy you can try and reseat the cpu. look on the mb to boot the mb needs a 24 pin cable and a 4/8 pin power cable make sure both are locked in. on the eight pin cable make sure they used the right 8 pin cable and not the video power six plus two cable. for the motherboard if they used a full size atx mb it should be sitting on 8/9 brass standoffs and held down by screws. the mb should not be touching the metal motherboard tray. if you think the power supply went bad try pulling the gpu and seeing if the mb will post with just the onboard video.