PSU boots for 1 sec then turns off

[kumaak47]

Hi i just installed an EVGA SR-2 1200w power supply into my comp the first time i booted it up worked fine but then went back and connected my hardrive it would constantly turn on and off even though mobo lights were on.

Specs* Asus P7P55D-E-DELUXE mobo
640gb western digital
GTX 460 1gb sli
Intel Core I5 750

 

[shovenose]

weird...recheck your connections

 

[Onus]

That suggests a short somewhere. See if the problem only occurs when that particular hard drive is connected.
Make sure you didn't plug an 8-pin PCIE power cable into the CPU power connector.