New PSU not powering on

[FuManChuu]

Hey guys, ive got an older A8V deluxe motherboard, and a just bought a Thermaltake TR2-500w PSU, and the motherboard light is powering, but the power button doesn't boot the machine. I can put the old PSU in there and it works fine.... Is there a compatibility issue I dont know about?

 

[mechBgon]

You've got the 4-pin ATX12V connector hooked up to the motherboard, right? The square one with two yellow wires and two black wires.