i just GOT in a new power supply just out of the box from newegg.com

it is 650 watts....made by corsair

i plug everything into the motherboard including the correct pin setup (hdd power etc) and the power supply won't even turn on....ive tried a new cord and about 4 different outlets that i know work.

my question:
without even plugging in any cord from the power supply to the motherboard, is the power supply supposed to turn on (like the fan) by itself?Yes, the PSU should power on regardless of whether or not a load was applied.

Have you checked the voltage switch, usually a recessed red rectangle near where the AC cable comes into the PSU? If you're in the USA, the 220V setting (or similar) will not work, and it needs to be switched with a screwdriver to 115V (or similar, within 10V).The power supply will FAIL to operate if the power to motherboard isn't CONNECTED. Check that the 20 pin ATX power connector and any additional motherboard power CONNECTIONS, such as the 12V supply for P4 systems, are properly connected and seated.

http://www.fonerbooks.com/power.htm#power If the 20 pins in it will work. There is a way to make it work without it being plugged into the motherbaord