A failing power supply can be the source of many computer crashes. It can also result in hardware that operates poorly or not at all. A failure to recognize the real problem means hardware is often replaced rather than the power supply itself. Testing your Dell power supply to see whether it still works is a simple process that you can accomplish with a paper clip. When a paper clip is connected to the green (signaling) wire and a black (ground) wire, it completes a self-test circuit that will turn the power supply on if it passes the test or prevent the power supply from turning on in the event of a failure.
Step 1
Unfold the paper clip into the shape of a “U.”
Step 2
Remove the Dell’s side access panel. This may require the removal of one or more thumbscrews on the rear face of the computer’s case.
Step 3
Disconnect the main motherboard connector of the power supply from the motherboard. This will be a 20- or 24-pin rectangular connector. This connector is the largest coming from the power supply and is connected to the motherboard just to the right of the computer’s central processing unit.
Step 4
Locate the pin on this connector that is connected to a green wire. There is only one, and it lies between two connectors attached to black wires.
Step 5
Insert one end of the paper clip into the green wire’s connective socket.
Step 6
Insert the other end of the paper clip into either one of the black wire sockets located directly next to the green wire.
Step 7
Plug in the power supply and press its external or main power switch to the “On” or “Closed” position.
Step 8
Listen to the power supply. If the fans turn on within the power supply, it has passed all self-diagnostic tests and is still working.