Question Power Supplies under no-load will not turn on

[cbbs70a]

Hello;
I recently cannibalized several functional and working PC's that were no longer in use, including 4 power supplies from three manufacturers. I yanked the power supplies and kept all of the wiring in place. However, when I simply tried to power them on one by one, none of them worked. My definition of working is to plug each supply into a wall plug and check to see if the fan is working. So right now I see two possible explanations, (1) I am missing something extremely simple, or (2) I've discovered that my superpower is the ability to stare at an electrical power source and completely suck the energy out of it. Any insight at all would be greatly appreciated.
Regards;
Frank

 

[DSzymborski]

You can't just plug in a power supply and turn it on. You need to jump the PSU to start it without a PC/motherboard power button. If not, a power supply that's switched on would never "listen" to a PC/motherboard telling it to turn on and off.

https://bit-tech.net/guides/modding/how-to-jump-a-psu/1/

I keep one of these in my PC toolbox.

https://www.amazon.com/Antrons-24-Pin-Jump-Starter-Bridge/dp/B00K38IKRY

 

[OF_freeCn]

Hello;
I recently cannibalized several functional and working PC's that were no longer in use, including 4 power supplies from three manufacturers. I yanked the power supplies and kept all of the wiring in place. However, when I simply tried to power them on one by one, none of them worked. My definition of working is to plug each supply into a wall plug and check to see if the fan is working. So right now I see two possible explanations, (1) I am missing something extremely simple, or (2) I've discovered that my superpower is the ability to stare at an electrical power source and completely suck the energy out of it. Any insight at all would be greatly appreciated.
Regards;
Frank

The PSU won't turn on UNLESS it's plugged into a motherboard. You can do a paper clip test (follow the instructions here https://www.wikihow.com/Check-a-Power-Supply ) to see if the PSUs are working without a motherboard.

 

[cbbs70a]

Hey;
Thanks for the quick replies. I definitely should of thought of that. Once I shorted the two pins, the power supply spun right up. Damn, I thought that I had found my superpower.
Thanks;
Frank