How to test motherboard with multimeter

Testing a motherboard with a multimeter is an essential step for anyone looking to get their PC up and running. Knowing how to check for faulty components or diagnose other problems can often save money and time down the road.

In this blog, we’ll explain the process of using a multi-meter to test your motherboard, so you can be sure everything is in working order before you put your system together. Let’s get started.

Symptoms of a bad motherboard

A bad motherboard can be a real headache for any computer user. There are a number of signs that can indicate a failing motherboard, such as random restarts, system freezes, blue screen errors, and even no power or display output. To help identify a failing motherboard, it is important to understand the symptoms of a bad motherboard.

The Computer Failing To Start

If you cannot get past the initial start-up screen, then chances are there is something wrong with either the CPU or your motherboard (particularly if other components seem to be functioning properly). Try reseating both components and see if this helps resolve any issues.

No Sign Of Life When Plugged Into A Power Source

No power or display output is another symptom of a bad motherboard, as this suggests that the processor is not able to interact with the other components in the computer.

This could be an indication your power cable has gotten loose or damaged but it’s also possible that there are issues with more integral parts like capacitors on your board which will require replacing them in order to fix it.  

Constantly Getting The Blue Screen Of Death (With A Boot Error Message And Sad Face)

Blue screen errors are also a sign of a bad motherboard, as this is the result of the processor being unable to access certain functions. Your board’s BIOS could potentially have corrupted itself, leading to blue screens when trying to start up Windows again. Try resetting it back to its default settings using a jumper on the Motherboard itself if available 

Sudden And Frequent CPU Restarts

Random restarts are one of the most common symptoms of a bad motherboard as the processor cannot keep up with the commands sent by the software.

Rarely does this happen due to problems related specifically to just one component, so ensure all other hardware is running correctly prior to pinning down the exact issue; for example, GPU temperatures should not exceed 80C during normal usage periods—check these regularly! 

Failure To Recognize Certain Hardware Components Like The RAM

RAM is often overlooked when troubleshooting PC failures; however, make sure all memory sticks installed onto motherboard slots correspond perfectly before continuing onwards in search for the culprit behind systems crashing randomly over time.

System freezing is another symptom of a bad motherboard, as the processor is unable to perform any operations.

 Dangerously overheating PC

Poor ventilation throughout the case coupled together high ambient room temperature can massively contribute towards system overheating due to heat build-up within tight areas meaning additional cooling fans are required immediately by the user/technician depending on the situation at hand here as well as checking on a regular basis too! 

If you experience any of these symptoms, it may be time to replace your motherboard.

How to test motherboard with multimeter?

Here are the steps to test a motherboard with a multi-meter:

Disconnect the motherboard from the power

To test the resistance in a circuit, you don’t need to have current running through it.

Disconnect your computer from the power source and give it about 10 minutes for the current inside the motherboard to completely drain out. Then you can move on to the next step.

Now set it to 200 ohms range

To measure resistance in ohms, you’ll want to set the multi-meter to the lowest range, which is 200 ohms and is represented by the omega symbol (Ω).

If you’re set up correctly, when you touch the two multi-meter leads together, the multi-meter should show 0 ohms reading.

You can also touch the two leads against the metal part of your computer to check for 0 ohms. If you get an “O.L.” reading, then you know something’s not right.

Detach the ATX connector

The ATX connector is what helps the motherboard get power from the Power Supply Unit (PSU). The PSU changes the AC voltage into a lower DC voltage that the motherboard can use.

When you want to access the pins of the PSU, you have to disconnect the power connector, making sure you’re careful not to break it.

Place probes on its chassis

To start, you need to check the resistance of the wires that connect to the PSU.

Put the black lead on the metal part of the computer and the red lead on each of the black GND wires.

These should show a zero Ohm reading on the multi-meter,, or else there’s a short circuit in the connector. Then move on to the colored wires, again putting the black lead on the metal part and the red lead on each of the colored wires.

This time, you’re expecting a reading of at least 50 Ohms – if it’s lower than that, then that’s your problem and you need to change the connector.

Test resistance on PSU pins

If the cables are good, you can move on to testing the motherboard’s PSU slots. You’ll need the specific ATX-20 pin chart for your motherboard.

Put the negative probe on the computer’s metal chassis and place the red probe on each of the black slots. You should get a zero reading from the multimeter for each pin. If you get anything other than zero, it means there could be a shortage in the PSU.

That could explain why the motherboard isn’t working, so you might need to replace the PSU or the whole board. The colored slots should have at least 50 ohms of resistance.

How to test voltage on a motherboard?

Here are the steps to test voltage on a motherboard:

Connect the device to the power supply

To test the voltage in the motherboard components of the computer, you got to hook it up to a power source to get it running. You also got to connect the 20-pin connector to the PSU.

Set multi-meter To 20 DC voltage range

To get accurate readings, set the multi-meter to the 20 DC voltage range. Look for “V– (with three dots)” or “DCV” on the multi-meter to indicate DC volt.

Back probe connection

The multi-meter leads are too big to fit into any of the openings to get in contact with the PSU slots that have power, so you use a thin needle to back probe the connection.

Evaluating results

You should expect a power supply of at least 2.5V on Pin 8 (PG or Power-OK). When you hit the reset button, this value should go to 0 and back up to more than 2.5V. On Pin 9 (VSB), you should see a reading of more than 5V, and on Pin 14 (PS-ON) the value should be between 3V and 5V.

When the power switch is pressed, the value of Pin 14 (PS-ON) should also drop to 0. If you get a different reading with your multi-meter, then it means there’s a fault in either the power connector or the PSU pin, so it needs to be changed.

This could be why your motherboard isn’t working. Don’t forget to check the image for the correct color codes and placements for each connection.

More Helpful Resources

How to test motherboard without CPU

How to control RGB on MSI motherboard

Different types of the motherboard and their functions

How to clean the motherboard with thinner

Fix the orange light issue on the motherboard

How long does a motherboard last

How to enable HDMI ports

FAQ

Conclusion

In this article, we have discussed how to test the motherboard with a multimeter. We hope you have learned what a multimeter is and how to use it properly. We also discussed what to look for when testing motherboards and how to test them for any potential issues.