Hello,

I have recently decided to save money and build my own computer. I purchased a case with a 420 watt power supply, a DFI Lan party kt400a, 512 mb ddr3200, and a video card and hard drive. The video card and hard drive are irrelovent for this question.

I switch on the power supply in the back of the case. The power supply makes a small hum for half a second and then stops. When I press the power switch in the front of the computer it does nothing. This led me to believe that my Leds, power switch, and reset switch were hooked in incorrectly. I reffered to the motherboard manual and found that they were hooked in correctly. I messed arround with them trying different directions to plug them in but the same thing happens everytime. Another note that may be important is that when I simply remove the switch it does the same thing.

Any advice would be beneficial.

Thank You.

it could be a power supply but then again i put everything in my new case and all the leds was indicating that it was hooked up right and when i hit the power button it wouldn't start and i took it back to the place i bought it from and they tested it the power supply and there was nothing wrong then they hooked it up and try to start my computer and it wouldn't start and they used a different switch and it started up it could be a switch that maybe bad

try taking power switch out, and using a screwdriver to short the on button pins (DO THIS VERY CAREFULLY AND LET GO IF IT STARTS OR MORE THAN A SECOND)

have you acctually plugged both of the motherboard PSU cables in (the big one and the small 4 pin one if applicable)

I had a similar problem, turns out my videocard must have somehow wiggled out of the agp slot, so i pushed it back in, computer started up no problem.

Incorrectly fitted video card, RAM or front panel connectors is the most likely source of the problem