post #11 of 11
Unless you somehow received two bad PSUs in a row, which I doubt, I think the problem is either a short between the motherboard and case, or a bad motherboard.

Motherboard shorts are usually around the mounting holes (check top and bottom of each, and add insulator washers as needed), unsupported corners (boards and cases flex, add rubber bumper foot at corners, sticky side toward case), and on the bottom when the CPU heatsink is held in place with metal hardware. The transparent coating on the motherboard is too thin and fragile to electrically insulate the metal hardware and prevent shorts; you need plastic or cardboard washers or sheets for that.

Also see if the heatsink is seated correctly because if it's on crooked, the CPU will get very hot instantly, and that will prevent many motherboards from turning on, despite the fact that modern CPUs can't be damaged by heat that's not from a blowtorch.