How do I trigger this PSU? \ VOGONS

How do I trigger this PSU?

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First post, by LChackr

Posted on 2025-05-27, 16:24

LChackr Offline

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Posts: 86
Joined: 2013-02-27, 20:36

This power supply doesn't have an external power switch and also doesn't have the normal obvious trigger connectors like typical AT PSUs.

Black = Ground
Blue = +12V
Red = +5V
White = Power Good
Yellow = -12V
Orange = -5V
Brown = +3.3V?

I assume that jumping two of the wires on P9 will trigger it? The wire colors on that connector are violet, green, and black (ground, I assume)? Violet and green wires don't appear on any of the wires for the rails so I am thinking they are signal lines.

I also am not sure what P10 and P11 are intended for, I am guessing that brown is +3.3V and it's spec'ed to deliver 14A on that rail. Since I can't power on the PSU I can't test to verify. 🙂

Reply 1 of 3, by luckybob

Posted on 2025-05-27, 17:45

luckybob Offline

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this is one of those power supplies from the transition to ATX. Used on many late Pentium 1 machines, including the Pentium Pro.

Its effectively an ATX power supply - with AT connections. its highly likely, if you short the green wire on P9 to ground, it should start.

Please be gentile with this power supply, these units are pretty rare.

It is a mistake to think you can solve any major problems just with potatoes.

Reply 2 of 3, by LChackr

Posted on 2025-05-27, 18:11

LChackr Offline

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Posts: 86
Joined: 2013-02-27, 20:36

luckybob wrote on 2025-05-27, 17:45:

this is one of those power supplies from the transition to ATX. Used on many late Pentium 1 machines, including the Pentium Pro.

Thank you and that's awesome, because I have a Pentium Pro build I am planning. I want to test this with a regular AT PC board first.

Reply 3 of 3, by LChackr

Posted on 2025-05-28, 00:25

LChackr Offline

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Rank: Newbie
Posts: 86
Joined: 2013-02-27, 20:36

luckybob wrote on 2025-05-27, 17:45:

Its effectively an ATX power supply - with AT connections. its highly likely, if you short the green wire on P9 to ground, it should start.

UPDATE! For anyone searching for the answer, this is the right one. Shorting the green wire on P9 to ground starts the PSU. Disconnecting the wire shuts it back down. Thanks!

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