The ATX 24 pin power supply connector is the standard motherboard power connector in computers today.
The connector itself is a Molex 39-01-2240 connector, often called a Molex Mini-fit Jr.
Note: The original ATX standard supported a 20 pin connector with a very similar pinout as the 24 pin connector but with pins 11, 12, 23, and 24 omitted.
Below is the complete pinout table for the standard ATX 24 pin 12V power supply connector as of Version 2.2 of the ATX Specification (PDF).
Note: If you're using this pinout table to test power supply voltages, be aware that the voltages must be within ATX specified tolerances.
You can see other ATX power supply connector pinouts in my ATX Power Supply Pinout Tables list.
ATX 24 pin 12V Power Connector Pinout (ATX v2.2)
| Pin | Name | Color | Description |
|---|---|---|---|
| 1 | +3.3V | Orange | +3.3 VDC |
| 2 | +3.3V | Orange | +3.3 VDC |
| 3 | COM | Black | Ground |
| 4 | +5V | Red | +5 VDC |
| 5 | COM | Black | Ground |
| 6 | +5V | Red | +5 VDC |
| 7 | COM | Black | Ground |
| 8 | PWR_ON | Gray | Power Good |
| 9 | +5VSB | Purple | +5 VDC Standby |
| 10 | +12V1 | Yellow | +12 VDC |
| 11 | +12V1 | Yellow | +12 VDC |
| 12 | +3.3V | Orange | +3.3 VDC |
| 13 | +3.3V | Orange | +3.3 VDC |
| 14 | -12V | Blue | -12 VDC |
| 15 | COM | Black | Ground |
| 16 | PS_ON# | Green | Power Supply On |
| 17 | COM | Black | Ground |
| 18 | COM | Black | Ground |
| 19 | COM | Black | Ground |
| 20 | NC | White | -5 VDC (Optional - Removed in ATX12V v2.01) |
| 21 | +5V | Red | +5 VDC |
| 22 | +5V | Red | +5 VDC |
| 23 | +5V | Red | +5 VDC |
| 24 | COM | Black | Ground |
