Can't get the power supply to stay on

I have a slim HP power supply that I got off ebay and I'm having trouble getting it to stay on when I plug it into the wall. As per the wiki, I've connected the green wire on the motherboard connector to one of the black ground wires. When I plug the power supply into the wall, its fan briefly spins, but then stops. I've also tried actually plugging the ATX+4 connector into my completed Sanguinololu 1.3a board to give it a load, but when I plug it in, the fan briefly spins and the Sanguinololu's red LED illuminates for a second, then goes out.

What am I doing wrong?

You probably need to put a load in the +5V rail. I have a 10 ohm, 10 W wirewound resistor from Radioshack on mine. It's a little hot but it won't burn. I probably could have put two of them in series.

brnrd Wrote:
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> You probably need to put a load in the +5V rail. I
> have a 10 ohm, 10 W wirewound resistor from
> Radioshack on mine. It's a little hot but it won't
> burn. I probably could have put two of them in
> series.

This might be it. Some power supplies require a load on the 5V rail to operate properly.

Hi, slightly off subject, though didn't think it was worth a separate thread but would this [www.ebay.co.uk] suffice as a power source for my up and coming Prusa mendel build?

Thanks in advance for any advice

Edited 1 time(s). Last edit at 09/20/2011 01:02PM by indieflow.

If there really are two separate 12V rails that provide 13 A and 14 A output, then it would be enough. Most heaters for ABS would be around 1 ohm which would require 12 A at 12 V so you can use the 14A rail. You can use other rail to power the rest of the electronics. Beware. My ATX power supply was supposed to have two separate 18A rails but I found out that there's only one rail after I tested it.

Edited 1 time(s). Last edit at 09/20/2011 02:56PM by brnrd.

Right thanks for that information. I've just purchased the Heatbed Mk2 which states it requires around 11A on wiki, so hopefully should be fine. Like you say it states on the auction for the power supply that it has 2x 12V supplies so hopefully enough!