How to Reconnect the Power Connections in your PC

In the course of troubleshooting or system maintenance, it sometimes may become necessary to disconnect and reconnect internal power cables. This article illustrates the types of internal power connections you may encounter.

In order to discharge standby power to the motherboard, replace a motherboard, troubleshoot some power related issues, disconnecting and reconnecting (also called reseating) the main power cable may become necessary. Right is an image of a 24-pin power connector. Some systems have a 20-pin connector instead. They are keyed so that the shapes of the connector housing matches the shapes of the power socket, ensuring it is inserted properly. When fully inserted, the center clip snaps into place. This clip must be depressed to unplug the connector from the socket.

Most motherboards today require 4 or 8-pin 12-volt supplemental power connections. The images below show the 8-pin power disconnected and reconnected. As with the main power, these plugs are keyed and have clips to keep the connection snug.

Right is an example of Fan Power Connection, also keyed to connect only one way. Motherboards may have 2 or 3 of these for powering and monitoring fans. One for the CPU heatsink fan, one for the rear and one for the front case fans. The black and red wires are for powering the fan, the yellow for monitoring fan speeds.

In addition to the above, there are 4-pin peripheral power, 4-pin floppy power, 6 and 8-pin Express power, and SATA power connectors to be familiar with. For more information about various computer power connections, visit Mark Allen's Playtool website.