Tech Inferno Fan 20 Posted December 1, 2014 Something that has been asked many times. How do I power on my ATX PSU? Having a ON/OFF switch on the back of the unit is not enough. What needs to happen is 20/24 PIN ATX connector's PS_ON# wire needs to be grounded to switch it on. How do do that? There are two ways: 1. Using the 'paperclip trick' to turn on the ATX PSU Connectiong PS_ON (green) to COM (black) on the ATX motherboard plug using a paperclip as seen on the left turns the power supply on. Means the 12V/pci-e power outputs will then be active. - for ATX PSUs with a OFF/ON switch : when when you attach the mains cable into the PSU and switch ON/OFF to ON the ATX PSU to ON, it will become active - for ATX PSUs without any OFF/ON switch :when you attach a mains cable into the PSU it will become active. If you require an OFF/ON, then wire through a on/off switch in place of the paperclip OR just pull the mains lead. There are many google images of how to attach the paperclip if the ones on the left are unclear. 2. Using a SWEX to turn on the ATX PSU A US$9 BPlus SWEX wires through the PS_ON# and COM leads in exactly the way as the paperclip trick does above. It does however include a nice on/off switch plus includes a JP1 connector which can accept an externally wired active_low signal to power on the PSU. 1 Quote Share this post Link to post Share on other sites
angerthosenear 266 Posted December 2, 2014 I would like to add something to this:If you somehow mess something up while pulling voltages off the PSU or the wrong pins when doing this. Some PSUs (that I've tried) have a safety system that causes them to permanently be off. If this ever occurs, remove the paperclip / switch the SWEX off, unplug the PSU from mains power, and wait a minute or so. Then can simply reconnect everything to get it working again.As a more temporary solution, you can also shove the paperclip on the "wire-side" of the 20/24-pin plug. I've done this when forcibly jump-starting a motherboard (to my surprise it actually worked).For the more adventurous (aka the dangerous method - not responsible if you injure yourself or others in any fashion), you can open up the PSU and solder the PS-ON (green wire) to the COM (black/ground). This way, whenever the PSU is plugged into mains power, it is switched on. I've done this for my bench-top power supplies for the cheap.For eGPU and other more permanent solutions I recommend getting a SWEX. It is a very safe and very reliable method. 1 Quote Share this post Link to post Share on other sites
Dschijn 329 Posted December 2, 2014 Also be aware that the PSU has to have some load when turned on. Don't just simply turn the PSU on without anything using the power. At least a fan or sth...I am using this "bridge" to start my PSU. Imho cheap and "safe": Caseking.de » Netzteile » Netzteil-Zubehör » Bitspower 20 PIN ATX - Überbrückungsstecker Quote Share this post Link to post Share on other sites
Puppydax 0 Posted June 19, 2016 (edited) I'm assuming the paperclip trick can be done directly on the PSU if fully modular, yeah? Edited June 19, 2016 by Puppydax Quote Share this post Link to post Share on other sites