Molex Power Connector

ATX Mother Board Pinout

Main Power connector

ATX Main Power
This page provides the connector style and pinout for the main power connector used on the ATX Motherboard.
The connector attached to the mother board is a 20-pin dual-row Molex connector, or similar [Male pins].
The Molex part number is 39-29-9042, from the 5566 series. Also seen; 39-01-2200, and 39-29-9202.
The mating connector coming from the power supply cable is a Molex 39-01-2040 [Female sockets].
Refer to this page for all other ATX header pinouts, or this page
BTX motherboard header pinouts with that link.

ATX Main Power Headed Connector Pinout

ATX Main Power Connector Pinout
Pin # Signal Function Cable Pin # Signal Function Cable
1 +3.3VDC Orange 11 +3.3VDC Orange
2 +3.3VDC Orange 12 -12VDC Blue
3 COM Black 13 COM Black
4 +5VDC Red 14 PS_ON# Green
5 COM Black 15 COM Black
6 +5VDC Red 16 COM Black
7 COM Black 17 COM Black
8 PWR_OK Gray 18 -5VDC White
9 +5VSB Purple 19 +5VDC Red
10 +12VDC Yellow 20 +5VDC Red

The pin out table above provides both the connector pinouts and wire colors for the cable assembly.
16 AWG wires for 300 watt power supplies
18 AWG wire is recommended for all wires but pin 11, which uses a 22 AWG wire.

Molex ATX Main Power Connector image

These connectors and cables can be purchased from any computer store.
Just ask for a 20-pin Molex ATX main power cable assembly or 20-pin Molex connector.
Additional Mother Board form factors and processor types are listed on the OEM MotherBoard Manufacturers page.
Memory Module formats and manufacturers are listed on the Memory Module Manufacturers page.

A few, but not many, computer manufacturers may use non-standard or proprietary components in their systems. The pinout for the power header listed on this page comply with the ATX specification. However some companies may use pinouts that differ from the pinout table above. First try to determine the pin out of the headers listed above from the manual that shipped with the computer, or review the ATX Motherboard specification then use these tables only after checking the manufacturing sources of data.

PC motherboard

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Modified 7/18/2015
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