Question Old AT motherboard connectors

gargoyle666

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Aug 10, 2016
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My oldest desktop PC has a baby AT-sized mainboard. The mainboard can operate using an AT power supply unit or an ATX power supply unit.
Originally it had an AT PSU which burnt out one day.
I was able to use an ATX PSU scavenged from an old PC. Everything works fine.

Curious: on the ATX PSU there is a spare white connector with 6 pins (black,black,black,orange,orange,red). I believe it is an AUX connector. Currently it isn't connected to anything.

I was wondering, should it be connected to part of the AT socket as well, or would that likely blow the mobo?
 
That plug is the supplemental 6-pin AUX connector. It was used in the original ATX spec from 1995 when most CPUs were powered off of 3.3v or 5v, and removed in the ATX12v 1.0 spec by 2000 when they added the 4-pin "P4" connector to supply 12v instead. Much later that morphed into the EPS12v 8-pin connector.

Boards that need it have a socket that looks like half of an AT connector but the wiring is completely different.
 

gargoyle666

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Aug 10, 2016
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The PSU is a Chieftec, 250W rated, possibly a generic model. I don't have the model number, the label is a bit worn. All I can say is that it's old.

The mobo doesn't have a separate half-AT socket so I'm going to leave it alone.

Thanks for the replies.