PLS HELP, IS MY MOBO DEAD?

I just built my first Computer and ive had things running smoothly for about 5 days, i decided to install the Call Of Duty that came free with my EVGA GTX 260 and right before the install window popped up my computer just shut off. Kind of surprised me so i tried to turn it back on, and nothing happened. No power at all. I thought maybe my PSU failed so i did the old paperclip trick and that worked. I plugged the 24 pin back into the mobo and... nothing, again. I'm not sure what happened but im not getting any power through the mobo. What could have happened? I would really appreciate any help.