Old power supply - pinout question

I have an ancient AT power supply here and I want to use it as an external 12v/5v unit for various projects and purposes (don't ask LOL ). Actually, I don't think it's even an AT unit as it only has a single 6 pin power connector where it plugged into the motherboard; I think standard AT units have two of these 6pin connectors. It was pulled from an ancient Compaq Presario 2200 desktop PC with Win95 LOL The power supply info is as follows: OTouch Electronic Co; Model SP9628; FIC P/N: 71-50326-00; a Compaq sticker on the PSU has the number 27194 on it; the Compaq spare number is 293814-001. I've done some Googling and got nothing. Anyway, the 6 pin power connector goes like this: RED - RED - YEL - BLU - BLK - BLK. The PSU has it's own on/off switch so I want to 'short' some pins in the 6pin connector so I can turn the unit on and off with the rear switch in order to power some external 5v and 12v devices and whatnot.

Thanks!
:-D

 

The 2 connectors (each in line 6 pin) you refer to were labelled P8 and P9

P8

1) Orange power good
2) Red +5 volts
3) Yellow +12 volts
4) Blue -12 volts
5) Black ground
6) Black ground

P9

1) Black ground
2) Black ground
3) White -5 volts
4) Red +5 volts
5) Red +5 volts
6) Red +5 volts

There was no equivalent of the green ps_on that you short to operate a modern supply. Switches in those days were hard wired self latching to switch the mains itself.

 

Thanks, but as I stated in my first post:

So, there is only one 6pin connector and it has no designation like P8 or P9 like a std AT unit would have. So, you're saying that I don't need to short any pins? Hmmm.. if that's the case, when it's plugged and I flip the rear power switch, it should turn on, and it doesn't (the PC I pulled the PSU from works so I know the PSU is OK), and the PC has a power button on the front, so this tells me that somehow the unit needs to be turned on in another (or secondary) manner besides just using the PSUs rocker switch.

From what I can tell, the single 6pin connector is more-or-less the same as the P8 header described above, except there's no Orange line; there's two Red lines instead of an Orange and Red. What exactly does "Power Good" mean?

 

The P8/P9 setup was introduced in 1980 with the XT and continued into the AT range.

Both had a straightforward on/off switch inline with the mains.

The Power_Good (also called Power_OK) is a +5v asserted by the power supply itself when all the rails have reached their alloted voltages.

Th PS_ON was added with the ATX series to allow 'soft switching', introduced with Windows 95 OSR2.

What voltages appear on your pins if you supply mains to the psu?

 

0.00v :cry

But the PSU was powering up an old 100mhz Pentium system, and it booted to the Win95 desktop so I know it's functional.....

 

You need actual loads, not just a voltmeter on swmps. they won't operate without a load. Some actually fail if run open circuit. 10 ohm 5/10 watt resistors should do.

 

Ahhhhh.... I see. It's not a big deal deal if I killed it, but I'll give it a go on Monday. I'm assuming just plugging in an 80mm fan or floppy drive would be considered a "load"?

 

You need to draw at least 0.1 amp, better , 0.5 amps from each rail.

 

I know this is a very old thread but I am hoping there are still those out there looking at it. I too have a very old XT power supply that dates to around 1984. It does have power in that it switches on - fan whirrs- and the Molex connectors to give a reading of 0.08v across both yellow/black and red/black. This PSU comes from a 1984 IBM XT – 5150, and I would love to get it going again. Any help or suggestions would be appreciated

 

I know this is a very old thread but I am hoping there are still those out there looking at it.

I have one of these on an original IBM PC XT 5150 with p8 and p9 mother board connecors. Although the fan turns, there is no output power to speak of. Putting a volt meter acros the molex gives Red/Black 0.8Volts and Green/Black 0.8Volts. I have opened the PSU and the only thing I could verify is the glass fuse is intact.

The specs are
Schrack Electronic
EG 071018-\d
Fabr. Nr 35835
IBM P/N 150438
E.G. Nr. 367
CW 24/84

Any help will be appreciated