This pinout is as standard ATX v.1 Except for PWR_OK and PS_ON.
20 pin MOLEX 39-01-2200 connector at
the PSU cable.
| Pin | Name | Description |
|---|---|---|
| 11 | +3.3V | |
| 1 | +3.3V | +3.3V/RS in Deskpro EN |
| 12 | COM | |
| 2 | +5V | |
| 13 | COM | |
| 3 | +5V | |
| 14 | COM | Aux COM in Deskpro EN |
| 4 | Fan OFF | may be +3.3VSB in some server PSU |
| 15 | +5VSB | |
| 5 | +12V | |
| 16 | +3.3V | |
| 6 | -12V | |
| 17 | COM | |
| 7 | PS_ON | |
| 18 | COM | |
| 8 | COM | RTN/RS in Deskpro EN |
| 19 | COM | |
| 9 | -5V | |
| 20 | +5V | |
| 10 | +5V |
Notes
- A Compaq SP750 Server Power supply (Such as PS 7431-1) uses the same pinout as an ATX power supply, except that PS_ON is inverted, and PWR_OK is replaced with 3.3VSB. The wire colors are also different.
- To use this supply with a normal ATX motherboard:
- cut PWR_OK and tie the motherboard side of the wire to 5v
- leave the power supply side of the wire unconnected
- use an inverter such as a 4096 or 7404 to fix the PS_ON signal
- tie the chip’s Vcc to 5VSB and GND to GND
- cut PS_ON, and hook the motherboard side to an inverter’s input, and the PSU side to the inverter’s output
- tie all remaining pins to ground
- An Inverted PS_ON signal is also common in G3 iMacs.