*UPDATE* How to turn on PSU without motherboard

slimeballzz · **Posted:** Tue Oct 24, 2006 5:10 pm

UPDATE
I finally found how to turn it on without the motherboard. Generally the paperclip trick (or any wire) conecting the green (pin 14) and any black wire together would turn it on but not in my case. In addition with the green wire connecting to a ground, I had to add a 50â„¦ resistor to pin 9 (purple wire, +5V) and to any ground wire.

I have an Enermax EG465P-VE that I want to use for testing fans and small electronic projects but it doesn't start up.

I've tried shorting the green and black wires but it doesn't work.
I've also tried connecting:
2x Hard drives
80mm Papst Fan
120mm Adda Fan
120mm Papst 23W fan

The 80mm Papst and Adda fan pulses but nothing happens to the rest.
I know the power supply works

Any ideas?

JazzJackRabbit · **Joined:** Fri Jun 18, 2004 6:53 pm **Posts:** 1360

I wouldn't recommend doing it, you shouldn't turn on PSU without load.

What do you mean for testing fans? If you mean for testing case fans to see which ones are quieter wouldn't it be easier to just buy 12V DC power block and wire it yourself? Should be easy and you don't risk blowing your PSU.

slimeballzz · **Posted:** Tue Oct 24, 2006 6:41 pm

JazzJackRabbit wrote:

I wouldn't recommend doing it, you shouldn't turn on PSU without load.

What do you mean for testing fans? If you mean for testing case fans to see which ones are quieter wouldn't it be easier to just buy 12V DC power block and wire it yourself? Should be easy and you don't risk blowing your PSU.

There will always be some sort of load on the PSU. But the problem is it won't even start up unless connected to a motherboard.

Sorry I forgot to note that I will be also using it to do some small electronic projects. It's a spare PSU sitting around which is why I don't want to go out and buy a power block.

disphenoidal · **Posted:** Tue Oct 24, 2006 7:40 pm

It's not like the power on pins on a motherboard, you have to hold the green wire at ground, not just momentarily connect them. If you maintain the connection between the green and black wires it should work.

slimeballzz · **Posted:** Tue Oct 24, 2006 8:13 pm

disphenoidal wrote:

It's not like the power on pins on a motherboard, you have to hold the green wire at ground, not just momentarily connect them. If you maintain the connection between the green and black wires it should work.

Yeah that's what I did. There's a paperclip joining the green to ground.

BillyBuerger · **Posted:** Wed Oct 25, 2006 7:15 am

I was thinking the same thing. I've got an old 330W PSU laying around. If I don't have any load, it shuts itself off almost immediately. I added an 8 Ohm 20W resistor to the 5V line and that kept it running. I tried using it to power a car amplifier. It works but sometimes had trouble handling the high current draw on start up.

slimeballzz · **Posted:** Mon Oct 30, 2006 4:51 pm

BillyBuerger wrote:

I was thinking the same thing. I've got an old 330W PSU laying around. If I don't have any load, it shuts itself off almost immediately. I added an 8 Ohm 20W resistor to the 5V line and that kept it running. I tried using it to power a car amplifier. It works but sometimes had trouble handling the high current draw on start up.

I tried putting a 4.7â„¦ 5W and a 120â„¦ 3/4 W in parallel on the 5V line and a 4.7â„¦ 5W and 22â„¦ 1/2W on the 12V line and nothing happens other than the fan pulsing for a quick second in the supply.

Is it the 5V or 12V line that needs the load?

UPDATE How to turn on PSU without motherboard

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