hi there i got a problem...my PSU is a OCZ fatality 550watts...i purchase a new parts(m/board,cpu(Phenom x 2 555)) the only thing im using back is the PSU,GPU(Geforce gtx 460) & Hard drive. I have a gigabyte GA-870A-USB3 m/board using ddr3 1600. my problem is...whenever i power the system on...it would boot up for a sec & shut down...power on by itself & shut down again. i try the PSU on another system(not so demanding like mines..onboard GPU,Athlon x2) and it boot up but when i try it back on my sytem...it start to freek out. I take out the memory,hard drive just to see if it boot up & its the samething...cant boot up. Can this be a PSU problem causing the system to act this way?? i try a 4pin PSU bcuz i dont have any more 8pin psu to test out ....i try it on the board & its the samething...dont know if it need the 8pin instead to boot up.