Troubleshooting Hardware Issues Lesson 001: Power Issues Part 2

When is a PSU considered faulty?

If it is not providing all three levels of DC voltage needed for a computer.

What should always be avoided when working with PSUs?

Never open up the PSU itself to try and work on it.

Why should PSUs never be opened up to be worked on?

It deals with high voltage that can shock you, hurt you, or kill you.

What should be done if it is verified that the power issue is caused by a faulty PSU?

Replace it.

What can be used to verify the functionality of a PSU?

A PSU tester.

PSU Tester

Small handheld unit that allows the connection of different PSU cables to test the voltages of them.

What is considered acceptable when testing the voltages of PSU cable?

A small variation of tolerance in the voltage measurements.

Where is the largest connector on a PSU tester usually located?

On the bottom.

What connector/s is/are usually found on the bottom of a PSU tester?

The motherboard power.

What connector/s is/are usually found on the top of a PSU tester?

4, 6, 8 pin connectors, SATA, and MOLEX.

What happens if one or more of the power cables connecting the PSU to different system components is faulty?

The connected components won’t receive proper power.

How are the power cables connecting the PSU to different system components tested?

Through the use of a multimeter.

What is considered a normal reading when testing power cables connecting the PSU to different system components?

0 ohms or slightly above 0.

What is considered an abnormal reading when testing power cables connecting the PSU to different system components?

Infinite or high number of ohms.

What does a high resistance level in a power cable mean?

That there is a break in the cable.

What does a tech have to do when testing detachable cables for continuity verification?

Check each pin on each side of the cable.

Why is incorrect voltage setting on a PSU not a common issue in modern systems?

Because there is no physical settings and the PSU handles this automatically.

What can the incorrect setting on a PSU cause?

Damage to the computer or the PSU or a fire or the system won’t turn on.

What should always be checked on a PSU?

If it has the switch to change the setting for the power input.

What should be ensured when using a PSU that has a manual setting switch?

That the right voltage is selected based on where you are in the world.