Note: The pin numbering and physical orientation of the connector can be found in diagrams from community sources like pinouts.ru. It is always wise to double-check the pin orientation with a multimeter before connecting any custom project.
Unlike standard ATX power supplies that turn on via a green wire shorted to ground, the D220P-01 uses a sense loop to detect when it is plugged into a motherboard. Out of the box, the unit sits in a low-power standby mode. Dell D220P 01 Power Supply Wiring Dell D220p 01 Power Supply Pinout 2