Bench Test a Power Supply

Essential Question: How can I tell if a Power Supply is working or not?

Mastery Objectives:

• Learn how to turn a power supply on with a paper clip.

• Learn how to determine whether a power supply is broken or not.

Background: There are several layers to why a power supply doesn’t work.  It could be that the power supply is bad, or it could be that the power supply does not send electricity properly to the motherboard.  Sometimes the computer does not turn on because it is broken, not because a power supply is bad.  In this lab we will learn how to test if a power supply is good or not without having the power supply installed in a computer.

Directions:  You will need to bench test a power supply to see if it works. In order to bench test a power supply, follow these steps:

1.       Find a power supply to test

2.       Get a paper clip

3.       Bend the paper clip into a U shape

4.       Insert one end of the paper clip into a hole for a ground wire (black wire) of the power supply connector that provides power for the motherboard.

5.       Insert the other end of the paper clip into the hole for the green wire. This is the wire that provides electricity to turn the power supply on and provide power to the computer’s on button.

6.       Plug the power supply in and move the toggle button to the “on” position or the “I” position to turn the power supply on.

7.       Test the remaining wires by following the chart below.  Remember the black lead for the multimeter should be grounded in a black wire while you change the red lead to test the orange, white, blue, yellow, and red wires. 

8.       Fill the chart below with your results.  Please indicate whether you used an analog or digital mutimeter to test the power supply.

9.       Determine if the power supply is healthy or not based on the chart below.