The power supply light stays on, but fans only start momentarily when switch is pressed. I replaced power supply just to make sure it was good, have same issue. Where do I look next?
There should be a little red switch on the back of the power supply, try clicking it up, or down, and see if it works :P
Though, that's probably a 1 in 100 chance haha. So my only verdict is your motherboard, or CPU. But we need more info, like does the PSU you tried work in another PC? Have you tried any components from the pc in ANOTHER pc to help isolate the issue?