How to Test a Bestec PC Power Supply

by Gabriel Dockery

Testing a Bestec PC power supply is essential to not only ensure that you are utilizing a safe power supply, but also that the power supply is not the cause of a malfunctioning system. Thankfully, Bestec power supplies conform with the ATX form factor and specifications, which allow for a signaling wire in the power supply's main connector for testing purposes. It is the signaling wire that we'll use to test the operation of the power supply.

Step 1

Find the main PC connection from the power supply to the motherboard. This connection will be either a 20-pin or 24-pin connector.

Step 2

Orient the connector so that the side clip is facing to your left. This clip is the one that attaches to the side of the main power connector on the motherboard.

Step 3

Unfold a paperclip so that it is in the shape of a U.

Step 4

Locate the green wire connected to the power supply's main connector. There will be only one green wire connector among the 20 or 24 wires.

Step 5

Insert one end of the paperclip into the green wire's connection hole.

Step 6

Locate one of the black wires immediately next to the green wire and insert the other end of the paperclip into its connective hole. There will be two black wires beside the single green wire; either wire may be used for this test.

Step 7

Plug the power supply in to an available wall outlet and turn it on using its power switch.

If the fan within the power supply turns on, then the power supply is indeed functional and without failure. The green wire on the power supply sends an operational signal to signify that the power supply is functional. In the event that a portion of the power supply was not functioning correctly, the green wire would not send the signal and the power supply would fail to turn on.


  • As counter-intuitive as it may seem, the green wire sends no discernible voltage that could cause any harm to the human being. Rather, it is merely a very low level electrical signal that is used to verify that the power supply is working and allow it to turn on. During this procedure you are at no risk of electrical shock, even if you plug the paper clip into the wrong connective hole, as in that case the green wire would not be grounded and the power supply would not turn on.


About the Author

Gabriel Dockery began writing in 2009, with his work published on various websites. He is working toward a Bachelor of Science in neuroscience in a transfer program between Ivy Tech College and Indiana State University.

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