Power Supply Tester

[DJKSea]

Hey guys having an issues with a power supply. I disconnect all the cables (20pin, 4 pin etc.) from the motherboard, and then attach them to the PC Doctor Power Supply tester in their proper placing (20pin in the 20 pin posistion, 4pin in the 4 pin posistion). I plug the power cable into the power supply and turn it on. The lights for the voltages come on ( +3.3V, -12V, PG, +5VSB, +12V, -5V, +5V, and then for the 4 pin +12V) Everything seems to be fine with the power supply. I then un-plug the cables from the PC Doctor back into the motherboard in their respective place. Plug back in the power cable. I hit the power button and the machine starts to boot for about 1/8th a second and then dies off. It doesnt allow me to do anything after that point. The light on the motherboard doesn't light up, the fans dont start, NOTHING. Im curious to know what could be causing this. Is their a power drain on the motherbaord? Is it possible for the power supply to pass all the voltage tests, and STILL be broken?

~Tek

[fwilson]

DJKSea,

The power supply tester included in the Kit tests output voltages not current.  Just like a car battery that shows 12 volts but does not have enough available Amps to turn over the engine so it can be with a PC power supply.  It would be cost prohibitive to deliver a power supply tester that could burn off 600 or so watts to properly load test a power supply. Most often when power supplies fail they fail all the way showing low or no voltage on the pins which the inexpensive tester will pick up.

There are many non power related things that can cause the behavior you describe. I would get a known good power supply and plug it into the system and see if the problem persists.  Don't bother hooking up the disks just the main power on the motherboard.  Make sure the power supply is grounded to the case with a test lead and see if it will boot up.

-Fred

[DJKSea]

Cool, thanks again! The new power supply worked great.