New build won't turn on

I just built a new rig
Specs:
Mobo: Gigabyte Z68MA-HD2H-B3
RAM: 8 GIG (4x2) Kingston HyperX 1600MHz
CPU: I5 2500K stock cooler
PSU: Topower ActivePFC 800
GPU: Nvidia EVGA GT 520

so basically my friend put it all together and it wouldn't turn so he called me over and I cant figure it out when I turn it on the power LED comes on but nothing happens and it turns off right after. I tried moving arround the cords at the bottem right hand corner of the mobo for the power switch and LED etc. We also tried 1 stick of ram and changing the 4 pin connector, booting without the video card and reset the CMOS. he also had to return his power supply to the place he bought it from because a resistor fell out and he tried turning it on with that power supply so he is wondering if that could have killed his mobo.