I just hooked up my new PSU to everything, only to try and turn it on with no success. The green light on my mobo comes on, but when I press the power switch on the front of my computer, the PSU's fan turns and the CPU's fan turns for about 1 second and then shuts off. I've double-checked all of the connections, I haven't rewired anything in 5 or 7 V as far as my fans go, and then I even tried to start the thing without it being hooked up to any peripherals (only the mobo and CPU) with the same result. What is going on? Is this a dead PSU? What else should I try to find out?