if nothing comes on that means that eithier the button on the case is bad, the motherboard isnt hooked up to the case's button, the psu isnt hooked up to the motherboard, something is wrong with the psu, the psu is not set the correct voltage for your country (the red switch on the back - 115 for north amercia), the psu isnt plugged in, or there is something shorting the motherboard out like a lose screw.