I have built a new computer, amd 2000 xp, elite k7s5a, leadtek winfast geforce4mx, fingers crossed turned it on and fan on processor span for one second and then all power stopped. If I turn the power supply off and then on and then press the start button I get one second of the fan spinning, by the way the fan on the graphics card does not spin. I have swapped out most bits the power supply the cpu fan even the graphics card works ok in another computer, I have tried the motherboard outside the case so there is no short. I am out of ideas any help gratefully recieved.

What Size power supply are you using?

350w and tried 300w

The 350 should be all the power you need.
It still sounds like a short somewhere.
I would start by repeating the Out of case tests.
Hooking up the P/S MB memory video floppy and speaker

try to boot it. If it still fails then you have it narrowed down.


I would also Double check all Jumpers (if it has them) especially the clear cmos

Make sure the power supply module's main power feed cable is securely inserted into the motherboard's connector. Sometimes this connection can be a tight fit. If there's a locking mechanism for the MB connection, check that it's engaged.
Also, connect the surge arrestor to another wall outlet, or bypass the arrestor and connect the computer power cord directly to a wall outlet.
Replace the arrestor if the latter works.

Also, try a different cable between the surge arrestor and the power supply module, and make sure the power supply module is set for 115 volts and not 230 volts.

Joe.....

Here's a Link that may Help.

http://pub65.ezboard.com/bk7s5amotherboardforum


Luck.

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....How long is a minute... depends on which side of the Bathroom door you're on. ......
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Thanks for the sugestions guys the link helped a lot as it has narrowed it down to the motherboard, it still wont work even out of the case the short must be on he board itself.
Joe

my friend had the same problem and had to find out the hard way by spending a 100 $ to get it repaired. His heatsink fan was not plugged in fully, check all the cables from the motherboard outwards, it could be the power supply cord jammed in the wrong way, the power supply probably has nothing to do with it unless it came with an 11$ case.