i have a corsair gs700 power supply i am building a new rig and i got everything put together and hit the power but all i get is a green led on the motherboard the fans dont come on and it dosent boot im running a gtx 780 and a sabertooth motherboard with an i7-2600s the power supply works when i put it back in my old setup however when my patience wore out i tried putting my 780 in my old setup and i got the hp start screen then a single short beep code which to my understanding means there is a psu issue and it wouldnt boot it is there something wrong with my psu or do i just need more power?