Second Build

Since my last computer i have upgraded the motherboard and the gpu! So i had this extra msi z68a-g43 (G3) motherboard laying around. Since i go down the shore every weekend of my summer i decided to build a lower end computer for my shore house. I used this motherboard (which was overclocked) and gtx 550 ti and 550 antec 80 plus certificated 8gb ram of ballistic corsair i believe. A old disk drive and a old hdd! The cpu i chose was the Intel core i-5 3450. I thought this would be an excellant mid ranged computer for my shore! To do miner gaming and movie watching and minor video editing. Today i bought a case which was the last piece to the puzzle i thought  . Right now i just assembled the whole thing and made sure all the wires were neat thinking nothing would go wrong. I powered up and all the fans and lights and bells and whistles turn out except the cpu fan. It stutters and stops stutters and stops and then finally kicks in and spins at full power. The computer shuts off approximately 8 seconds after it initally powers up. After it shuts off it waits around 2 seconds and repeats itself. I have took the motherboard out re did the standoffs, reseeted everything. Unplugged certain things. Tried torubleshooting but i am still stumped. Any help would be greatly appreciated.


Btw i thought that it was because the motherboard was recentlly used for ocing my other computer. So i got all excited and cleared the cmos with the connector and removing the cmos battery. Nothing changed it conintued to do the same thing.