My first thought is a dead power supply. What brand psu unit did you install? Does the psu fan spin?
edit...always assume that there is AC power in the motherboard. Don't touch anything.
edit...connect all of the wires again. Make sure there is power at the outlet. Make sure the psu is set to 115 volts. Make sure switch on back of psu is 'on'. Try the power button again. Does the fan on the psu spin? Does the LED on the motherboard light up? If it does you can backprobe the motherboard connector with a volt meter: (or buy a psu tester...$15-25)
(Do you have the CPU power cable plugged in? Should be 4 or 8 pin.)http://www.hardwarel...2006-03-25.htmlhttp://www.realworld...i...0000000&p=4
Here's a technique of shorting the black and green wires. Make sure the pc is unplugged and throw the switch on the back of the psu to the off position and short the green and black wires on the motherboard connector with a paper clip or piece of wire. Plug it in and throw the switch on the back of the psu. Does the fan on the psu come on? Anything else happen?http://www.sysopt.co...cle.php/3532716
If your not getting anywhere, take the motherboard out of the case and connect the keyboard and monitor and short the two switch pins on the motherboard (with a screwdriver)where the switch is normally plugged in. Anything?
Keep in mind, the psu should always be connected to a load when turned on.
Just making sure...you did use standoffs when you installed the motherboard?
Edited by macten, 30 May 2007 - 11:08 PM.