You can bypass the mobo power switch with use of a paper clip but it is a little nervey!!!!! You go to pin 14 on the 20 pin rail and insert the paper clip from pin 14 (green) to an adjacent balck ground while the power is off and unpluged from the wall. Plug the psuback in and turn the switch on form the psu and it will boot. Also, I have removed the swtiches from an old case and used those for circumstances just like yours. If you have an old case around just strip out the front side connectors like the HDled, reset and power SW. All you need to do is pull the power switch from the current case and insert the test switch. If it boots regularly it's the switch and you need a new case. If it is not the switch...I'm giong with a new power supply.
