Power supply works outside of case...

[crorr]

I got a new power supply for my HP pavillion p6404y. It's a 650w Apevia Java. Its nice and everything plugs up fine but when I turn it on inside the case, nothing happens. I know the power is circulating because i troubleshot(?) it from the apevia website. They said to create a short on the 20/24 pin connector to see if it spun. I tried it in the case. Nothing. I tried it out of the case, and it worked. What am I doing wrong? Why is my psu shorting in the case?

 

[crorr]

Update: The psu works when I don't plug in the 4 pin connector to the mobo. Just the 20/24 pin. Hmmm.

 

[crorr]

So will not plugging in the 4 pin molex do anything to my system? Apparently, a cpu won't turn on unless its plugged up. Mine's running fine without it plugged in. What are my options?