How to turn on an ATX power supply w/o mobo?

bobcrotch

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Mar 12, 2003
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I've never really had a need to do this but i'd like to hook up some fans in the shop for exhaust when soldering. Plus now that i thought about it i was just kinda curious, so anyone know howto do this? Or should i just go dig up an old AT unit?
 
I was actually wondering about this myself the other day, not sure how myself..would be cool to kno w though! :D
 
I'm pretty sure it's the green wire and any black wire...give it a shot and see if I'm right :p
 
On the ATX connector, short the green wire to any of the black ground wires.

The power supply will start.

It will not remain that way unless you keep it shorted, which I don't think is a good idea.

Personally, I'd dig up the AT power supply.
 
just get an atx power switch and splice it in or what? wich wire to wich wire?

hehe...try it, yeah thats the ticket there boss =b


Edit: Ok i was also wondering that, i know it's a momentary switch on the mobo, but it holds the circuit closed to keep it on? hmm alright i think i have an old AT somewhere, either that or work does hehe.
 
Look in the Case-Mod FAQ in the cool cases forum, it will have a guide under Power Supplies.
 
"Find the ATX mobo plug, find the green wire, (should be only one, if there are multiple green wires... then your PSU sucks, i wouldn't go any further), and take a piece of a wire so that you can connect something, than find a ground wire (should be 6, these should be black), and connect the green wire to the black wire, basically by shoving the third piece of a wire you have into both of those two plugs"

Stolen from the FAQ so you guys know too.

Hey you were close majordomo, not just trying to kill my fat ass =b
 
Originally posted by bobcrotch
"Find the ATX mobo plug, find the green wire, (should be only one, if there are multiple green wires... then your PSU sucks, i wouldn't go any further), and take a piece of a wire so that you can connect something, than find a ground wire (should be 6, these should be black), and connect the green wire to the black wire, basically by shoving the third piece of a wire you have into both of those two plugs"

Stolen from the FAQ so you guys know too.

Hey you were close majordomo, not just trying to kill my fat ass =b

He wasn't just close - give the man some credit :p
 
Do u not have to have a load attached to get the PSU to power up as well? ie if nothing is connected then it will not power up?
 
Once you have made the patch, all you have to do is plug in the PSU and it cranks right up just like an AT PSU :)
 
just carefully short the two pins together on the motherboard that you normally connect your case's power button lead to. (like with a screwdriver)
 
Originally posted by Syphon Filter
Do u not have to have a load attached to get the PSU to power up as well? ie if nothing is connected then it will not power up?

Well that's debatable. I've used an old crappy Deer PSU for projects before without much of a load (about 1/8W maybe) and it worked just fine. But I've heard that it's best to put something like a 25W load on one of the primary lines (3.3, 5, or 12) - but I can't remember which...
 
runatx360.jpg


The green wire to any Black wire will do. Here is some linkage for you:

Power Supply Testing Unit Mod - ExtensionTech.net
 
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