How to Test a Motherboard with A Multimeter?

Computers are not reliable. No electrical device is. No matter how many guarantees you have been provided with or how long the dates are on the warranty card; electric appliances such as computers are uncertain.

The uncertainty lies with the motherboard too, the assembling tray of your CPU that carries out an essential function of carrying and communicating between other components.

Are you facing random computer crashes and have absolutely no idea why is it happening? Have you tried out troubleshooting after your screen went blue or black several times? Have you had your PC components keep failing even after replacing them?

If the PC wouldn’t start, stop out of nowhere or make weird noises, the possibility is the motherboard has got serious issues.

This article tells you how to test a motherboard with a multimeter. It may sound scary and technical right now, but not when you read and follow all instructions carefully and take all precautions.

It is better to test the issue at home. Not only will it help you save a couple of bucks that you might have to pay for testing but is also going to save a ton of time that you’ll have to spend in the process.

How to Test a Motherboard with A Multimeter

The foremost method of testing a motherboard at home is with a multimeter. You can check for the voltages being incorrect or for a short circuit that causes computers to be dysfunctional.

If the motherboard is because of the incorrect voltages, or because of a short circuit, you can easily identify them with a multimeter and then find a fix for the problem accordingly.

Let’s see how to do it:

For DC Voltages

The multimeter can be used for checking the DC voltages of the motherboard. If the power supply is incorrect, obviously you will face problems in the functioning of the computer.

Follow the simple steps given below to detect any issues related to DC voltages in the motherboard.

  • Before you insert the multimeter into the circuit, ensure that the computer has an AC supply and the ATX connector (20 pinned) is in.
  • Now connect the multimeter and set it to 20 volts.
  • Bring the black probe in contact with either of the GND pins (15, 16, or 17)
  • It’s time to bring the red probe into use.
  • Probe pin 9 which is VSB. It will be purple in color. It should be at 5 V. In the case of the reading shifts from 5 V to any other reading, you can conclude that there is some with the PSU.
  • Again using the red probe, probe pin 14, this time you should observe a reading between 3 V to 5 V.
  • Then, press the PC power button.
  • Observe that the PS_On value is dropping to zero. If it doesn’t drop to 0 and there is any other value being displayed on the meter, you know that the problem lies with the switch.
  • Use the red probe again this time to check pin 8. It will be gray in color. It provides information about Power_OK. Check if the reading is 2.5 V.
  • Go ahead and start the computer. The Power_OK reading should drop to 0 and then come up gradually.

For Open/Short Circuits

We recommend all users to first check the Voltages by the method mentioned above and then get on to check for an open circuit, commonly known as a short circuit.

To check for open/short circuits using a multimeter, follow the steps mentioned below:

  • Remove the computer from the main power source
  • Press the power button several times to drain any battery or charge in the system
  • Now set the multimeter to 200 ohms. This is the resistance. Upon touching the leads of the probes the reading will become zero.
  • Next, you need to do is remove the TX connector.
  • Use the black lead to check the DC connector and the red lead to check the power supply unit pin. The reading should be zero.
  • Let the black lead be on the chassis.
  • Using the red probe, check the values of the colored pins on the DC connector. They must possess a value of 50, or more than 50.
  • It is now time you remove the motherboard from the CPU. The plate should be in your hand disconnected from all leads.
  • Using the red lead check values of pin numbers on the ATX 20 pin connector.
  • All of them must indicate zero.
  • If the reading is anything other than zero, you know that the problem lies with the connector. It can easily be resolved by replacing the connector. You can get a new one from a computer store and it doesn’t even cost much.

For bigger problems, the entire motherboard will have to be replaced.


If your computer is showing weird issues, most probably the cause is underlying in the motherboard. The easiest way to check a motherboard is through a multimeter.

In the article, we have answered your question “how to test a motherboard with a multimeter?”

Hope you now know what to do and what not to do. Do not ignore the signs your computer shows and keep checking the motherboard as your first priority.

Note that such issues cannot be fixed and you might have to replace the motherboard. If not, be prepared for the consequences other components of your laptop will have to face one by one.


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