I just got my power supply, and I wanted to fire it up and test a couple of my new fans. HOwever, My psu isn't installed in the case or anything yet. I just have it out of the box and plugged into a few of my case fans and such. Well I turn on the psu and it wont fire up. NOthing. The fan wont spin nor does it supply power. Will the PSU only turn on with the atx pins and other aux power pins plugged into the mother board?