okay. there is a good chance your motherboard might be dead. Turn off and unplug the power supply. Take out the big plug going to the motherboard. its the 20/24 pin depending on your computer. Right beyond the connector look for the ONLY green wire that's surrounded by 2 black wires on the power supply. Make sure the power supply is unplugged. Take a paper clip, you may have to cut it to size, and stick one end into the green wire pin, and one in either of the black wire pins that are on the left and right of the green wire. plug the power supply back in but don't let the paper clip lean on anything. if the power supply comes on, its not the problem. This works on any power supply. Try it with both the ones you have. Also the problem could be the switch going to your motherboard from your computer power button. make sure it's properly plugged in. it could be the power button if your power supply is working. Or worse off your motherboard could be dead. Next, if you still have the problem, hook the power supply back up to the motherboard and plug the computer in. unhook where the power button connects to the motherboard. you will see a couple pins, where the plug should be. take a philips screw drive with a plastic handle...or one with a handle that doesn't conduct electricity. Touch the pins together with the screw driver, by touching 2 of the pins together the computer should start if everything is hooked up right. It varies for each make of computer of which 2 pins will start it by making the connection. Most motherboards should have a green light that comes on when they are getting power, even when the computer is turned off. Also try plugging it into a different power receptacle if you haven't tried that yet. Oh and there are no fuses you can acess. i hope i helped, ive been in the same situation before. Heres the link on testing a power supply: http://www.overclock.net/faqs/96712-how-...
Source(s):
http://www.overclock.net/faqs/96712-how-...
my experince
Building computers
