instructablesImage: instructablesNextPrev The wires on the main 20 pin (or 24 pin) connectors are color coded. These are the same for all ATX power supplies: 3 wires are orange; +5V wires are red; -5V wires (if they are present) are white; +12V wires are yellow; -12V wires are blue;ground wires are black. The green wire is the "power on" sensor. Turn a Computer Power Supply into Bench Power | Make: Is this answer helpful?Thanks!Give more feedbackThanks!How can it be improved?How can the answer be improved?Tell us how A Maker's Guide to ATX Power Supplies: 6 Steps Background Information & Suggestions. So, you want to hack an ATX PSU, but you don't really Wire Colors & Functions in the PSU. Upon opening a PSU, you will find that it is a jubilee of wires in The ATX Connector. The two common ATX connectors are 20 and 24 pins. There are also 20-pin Other Connectors. In addition to the ATX connector, PSUs will have some or all of the following See all full list on instructables What is the wire color coding of ATX computer power supplies wwwdguide›Faq›Hardware FAQWhat is the wire color coding of ATX computer power supplies ? Computer power supplies (PSU) convert AC to low-voltage regulated DC power. Most modern desktop computers conform to the ATX standard, which supplies three positive rails: +3, +5V and +12V. All about the various PC power supply cables and connectors If there are no labels then you can usually use wire colors to tell the two kinds of cables apart. An 8 pin 12 volt cable has yellow wires on the same side as the connector clip. An 8 Pin PCI Express cable has black wires on the clip side.