How to turn on PSU without motherboard?

[N3dot]

How can I turn on an ATX-PIV 400WATT power supply without connecting it to a motherboard? I tried connecting the green cable (PS-ON) to several black cables (COM/GRD).
- This model doesn't have a switch.

 

[essenbe]

If you unplug the PSU, jump the Green connector with any Black pin and plug it in, it should be on. I usually use a paperclip bent in a "U" shape.

 

[Dude]

No switch, does it have a button? As far as the wire it should be the black one right next to the green

:ar: How to use a PC Power Supply as a Lab Power Supply - MicroAutomate

 

[fireberd]

I tried connecting the green cable (PS-ON) to several black cables (COM/GRD).

If you jumpered the green to a black and it didn't turn on, that would indicate a defective power supply.

 

[N3dot]

I tried jumpering the green connector with several black connectors with no success. Its works fine when connected to the motherboard. It doesn't have a switch/button.

 

[Dude]

that only test the power up signal, if it works for the motherboard then exactly what are you trying to do?

 

[fireberd]

Good point, Dude. It works, or at least it powers on with the PC power switch.

 

[N3dot]

I want to power it without connecting it to the motherboard.

 

[Dude]

To use as power for something other than a computer?

 

[Lady Fitzgerald]

When I was prepping my case for my new rig, I did it to make sure the custom cables were wired correctly and to make sure the fans worked ok. It also made sure the PSU worked.

 

[fireberd]

Powering a power supply without a "load" on each voltage does not guarantee the power supply is good. The power supply "testers" that are available will allow powering on and some will sense voltages, but as that does not put the various voltages under load it does not guarantee the power supply is fully operational.

But, if it will power on when connected to the motherboard, then it will power on if the Green is jumpered to the Black. I suspect a pin is not being inserted fully (making contact) in either the green or black pin and the reason it doesn't power up out of the PC.

 

[N3dot]

I want to use it as a "lab generator"

 

[Dude]

:ar: Convert to a lab

   Warning

Working in a PSU can kill you

 

[Lady Fitzgerald]

:ar: Convert to a lab

   Warning

Working in a PSU can kill you

X2 on the warning! People have been killed from opening up PSUs.

If the PSU has a switch and is fully modular, there would be no need to open it up. Just put a jumper in the 24 pin socket so it will come on when the switch is thrown. Output can be taken off the other sockets.

Plan B for a non-modular PSU would be to put the PSU in a case to hide the external wiring. Wires can be run from a SPST switch to the socket on the 24 pin cable or, if you don't plan on reusing the PSU in a computer just cut the green wire and a black wire from the socket and run those directly to the switch. The same would apply to the rails you would be tapping off from to go to binding posts, etc. on the case. You could get fancy and add switches and even voltage meters to each output.

Either option would eliminate the need to open up the PSU, exposing yourself to danger.