you can also buy a momentary switch from radio shack and attach the wires to it. It's easy to do as the switch has no polarity. If your handy with a dremel you can drill a hole in the case and attach the button to the case...making a new power switch.http://www.radioshack.com/product/index.jsp?productId=2062496
If the pins we're pulled from the motherboard then you have another issue. if you examine the board carefully there may be some indicators around the front I/O panel that will tell you which two are for power. If your feeling brave you can take a small flat tip screw driver and touch to pairs of pins (up and down) one of the pairs should turn it on.