Re: How can i test the case power button?
I usually, when building/testing scrap systems, just grab a 3mm straightblade and short the 2 switch pins.
If it still doesn't turn on, unplug the 20 pin connector, and short the green wire to ground (make sure you're insulated from any metal or wires) while the PSU is plugged into a load, and see if it kicks on.