I got three 500w Apevia power supplies. I'm having a problem with one of them. It comes on, but it wont power my motherboard. The motherboard posts an FF code and that's it. I tested the other two and a 500w (cooler master) on the same motherboard, and they all power up the motherboard fine. I called Apevia to RMA and they said I had to test it with a volt meter and make sure the voltage was wrong before they will RMA. Next I used a paper clip to jump the PSU and tested the voltage of every wire on the 24 pin and the 4 pin cpu plug. All the wires tested correct (12v yellow/5v red/3.3v orange). Im not sure about the gray (power ok) wire. I checked it and it read 5v. So if all the voltage is testing out fine, what could be wrong?
That kind of test tells you nothing really, since there is no load on the unit. Try testing the voltages when it is all connect up to the motherboard and powered up. It sounds to me like its a bad unit if all the other power supplies work connected up to that board.