<p>The ATX 4 pin <a href="https://www.lifewire.com/power-supply-unit-2618158" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">power supply</a> connector is a standard <a href="https://www.lifewire.com/motherboards-system-boards-and-mainboards-2618154" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="2">motherboard</a> power connector used to provide &#43;12 VDC to the processor voltage regulator.</p><h3>ATX 4 pin 12V Power Connector Pinout (ATX v2.2)</h3><p>Below is the complete pinout table for the standard ATX 4 pin (2x2) 12V power connector as of <a href="http://www.formfactors.org/developer%5Cspecs%5Catx2_2.pdf" data-component="link" data-source="inlineLink" data-type="externalLink" data-ordinal="3">Version 2.2 of the ATX Specification (PDF)</a>.</p><p><strong>Note:</strong> If you&#39;re using this pinout table to <a href="https://www.lifewire.com/how-to-test-the-power-supply-in-computer-2626129" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="4">test power supply voltages</a>, be aware that the voltages must be within <a href="https://www.lifewire.com/power-supply-voltage-tolerances-2624583" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="5">ATX specified tolerances</a>.</p><p>You can see other ATX power supply connector pinouts in my <a href="https://www.lifewire.com/atx-power-supply-pinout-tables-2624590" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="6">ATX Power Supply Pinout Tables</a> list.</p><table border="1" cellpadding="2" cellspacing="0"><tbody><tr><th>Pin</th><th>Name</th><th>Color</th><th>Description</th></tr><tr><td>1</td><td>COM</td><td>Black</td><td>Ground</td></tr><tr><td>2</td><td>COM</td><td>Black</td><td>Ground</td></tr><tr><td>3</td><td>&#43;12VDC</td><td>Yellow</td><td>&#43;12 VDC</td></tr><tr><td>4</td><td>&#43;12VDC</td><td>Yellow</td><td>&#43;12 VDC</td></tr></tbody></table><p><sub>The plug (male) is a Molex 39-01-2040 connector, the vertical receptacle (female) is a Molex 39-28-1043, and the right-angle receptacle is a Molex 39-29-1048.</sub></p><h3>More Information on the ATX 4 pin 12V Power Connector</h3>