How to power up an ATX Power Supply without a PC!

In this instructable i will show you how to power up an ATX Power Supply without a PC.

Maybe in some cases you want to test an old CD-Rom Drive or something else.
All that you have is a PSU from an old PC an a wire.

Here I show you how do to it.

Step 1: Search!

Just look after the green wire in the cable tree from the PSU.
Follow it to the 20 or 24pin ATX plug.

The green cable is in a way the "reciever" you need to power up the PSU

Comments

[smithrickya]

When I did this, mine briefly fires up and then shuts off on it's own. Any idea why?

[KevinAlien26]

thanks amigo, I have an ATX power supply in English with labels for each color, and another what appears to be Japanese with no labels. The English ATX is just plug and use no questions asked, the other however i thought was scrap.You saved me from tearing it apart!

[craig c]

If you have a DELL PSU instead of an ATX, theres a grey wire in the corner and a black one right next to it, just short them out instead of a green one to get same results.

[Toulouse]

Thank you ! I appreciated this info.
Working on a cnc machine, have a dell psu I'm using as the power supply.

[arzola1]

Thank you I needed this info

[Vinsu]

Great! Had forgotten this. Now to make use of my spare PSUs...

[FixedHDD]

Glad you like this! You're welcome :)

[swood11]

cooler master rs 500, Why is this not working for me, the power supply was fine before i started this project. i jumped it once and it worked but now its not working for me...

[spasysheep]

They need a small load on at least one of their lines (12v/yellow, IIRC) or they cut out for safety reasons.

[fjr_scoot]

Your English is better than most Americans! Thanks for a great instructable!

[kjdhfgdjkfhk]

did that but make a weird noise and gives only 5v i need 12v now what?

[cwagey]

The easiest thing to use to test a lot of devices that need a 'load' connected in order to operate, is a lightbulb. In this case, use 12volt automobile brake light bulbs, they don't cost much and they limit the current draw when they light up because the resistance of the filament increases.

[hore]

what devices, how about hair dryer, can i connect it with hair dryer..

[FixedHDD]

and i thought hair dryers are going to be plugged in to the outlet.... But anyway, you can connet everything that works with 12V, 5V or 3.3V.

[hore]

alright. thank u.

[hore]

my questions can i connect wire(green one) like in the picture with soldering iron , will it work, or i just gonna blow something.

[FixedHDD]

Soldering will be fine...

[FixedHDD]

sure you can. Does your PSU have a switch? Well then it is no problem at all.

After all my work in this instructable I ended up with a PSU having two switches. You can spare one if you solder the green to the black wire.

[hore]

how about power, what im trying to say is soldering iron might received more or higher voltage, could this possibly happen.

[burekmaker]

I would like to know how to start ATX power supply without a PC with one button click and release (that the switch is not ON all the time like in this case, but only for a few moments when you press button - like when you press power button in PC when you want to start computer).. if you know what I mean.. tnx ;)

[FixedHDD]

Well, to keep the PSU up and running the green and the black wire must be shorten permanently. A pulse switch doesn't work.

Buf if you are familiar with working with relays and stuff you could do this.

[gamera_the_brave]

Nice work mate :)

I've been looking for a simple way of getting my PSU to work without a motherboard, and it doesn't get much simpler than this!

Thanks.

[vectorges]

I have converted two ATX supplies (successfully) to power lights in my kitchen. Now I have two more that don't power up. I shorted the green wires. I put a 10w 10ohm resistor between a red and black. I did something with the purple. Any other suggestions?

[FixedHDD]

What did you with the purple one? The purple one is the 5V+ Standby Voltage, the current, witch powers the RAM during standby (otherwise the data stored in the RAM would be lost)

Don't mess with other wires instead of green and black (will power up the PSU like i wrote) and orange, red and yellow for the currents 3.3, 5 and 12 volt.

[jj.inc]

I need to know what I am missing because don't more companies than ATX make power supplies, like mine is a NZXT

[FixedHDD]

I think I don't understand that properly... ATX is not a company its an industry standard for PC power supplies. Any PSU that you can buy today is a ATX pwer supply.

[jj.inc]

,but ATX still has standards for things like motherboards

[jj.inc]

aaa, ok, thanks

[robbe47]

goede instruktable heb zelf drie pouwer boxs geprobeert het werkt uitsteken --dikke draat zware schakelaar en klaar

[Solderguy]

Wow. Thank you so much for this instructable. I can now transform my old power supply into an awesome bench power supply!

[rayyashi]

Thanks for your info i'v been looking it up to see how it can power hid xenon 35w thanks would you please show where to put a resistor or does led on 5v do the trick?

[FixedHDD]

i think an LED would do the job too!

[srilyk]

 Excellent, simple, clear instructable. Great job!

[KR-S]

thankyou!! this is exactly what I've been looking for. so simple too:)

[computerwiz_222]

Awesome! I have seen this on other sites, and I never fully understood it. One thing to mind is that if there are no devices, the capacitors in the power supply will begin to squeal, especially in the low end power supplies. What you may want to do is put a resistor on it to allow it to drain some current off as heat. I have seen cars running off of the 12 volts produced from the PSU. Not starting it, but when testing out new decks and amplifiers, a computer PSU is a good source of about 15 amps of 12 volts.

[hominid]

Ditto, Now I understand the green wire mystery that other instructables do not make clear.

[FixedHDD]

so, it should show how the basis is done. if then someone want to paint it or tie up this nasy cable tree a bit nicer.... its merely a matter of fantasy!

[FixedHDD]

thanks for the comments;-)

[underwhelmed]

Great Instructable. Your English is better than my German, and I lived there for 3 years. Of course, I was 7, but still.

[zuner2012]

I always love it when people start out saying their English isn't the best. They always have better English then *teh* people growing up with it. Nice instructable, thanks a lot for the tip.

[FixedHDD]

Hehe thanks a lot! I mean, posting instructables here or comments at youtube are very helpful for writing essays in the english lessons at school. I just had to write one last thursday.

[Sky_Marshal]

Excelent job, I'm going to use my PSU to charge a capacitor bank for a railgun. =-)

[twitch2009]

Dude your english is fine. thats Awesome

[teacherlau]

your English is good enough! awesome work

[pcludeg]

vary good project

[Unit042]

This is so simple! I never woud have guessed how to get these things running without a motherboard attached. I've got a couple of these things just lying around, and I'm also in need of a reliable +5v supply... I'm so doing this!

[John Smith]

My power supply wont start using this method unless I have something connected to it. Like a CD drive, or something.

[Itsgoofytime]

Add a power resistor, 20ohm 10 Watts.

[John Smith]

thanks!

[FixedHDD]

yep, you must connect something to the PSU otherwise it won't start up. i have already written this in the NOTE box in this instr.

[bleachworthy]

well, it's a bit more crude than the others on instructables, but it does work.

[thinkahead]

Your idea is a lot like this one... Use-that-old-PC-Power-Supply-as-a-high-current

[!Andrew_Modder!]

wow really, thats all?. nice

[nedfunnell]

Also, you won't get full power output on the 12v rail unless there is some load on the 5v rail. Not sure of the physicist explanation for this, but if you want to get more than an amp or two off of the 12v rail, load down the 5v rail with some auto light bulbs or something else that will pull an amp or two.

[GorillazMiko]

Great job on the pictures, I never knew this was possible either, great job! +1 rating.