How to Test a Motherboard with a Multimeter?

Multimeters are essential tools for testing almost any electronic device, including computers, televisions, and more. A multimeter is a handheld, battery-operated tool that tests electrical components. It measures voltage, current, resistance, capacitance, and frequency. They are used to test almost every type of electrical component, and they’re inexpensive!

If you’re looking to build a computer, you’ll need to know how to test a motherboard to make sure it’s working properly. A motherboard is the brain of your computer, so you can’t just blindly plug everything in and hope it works. You have to make sure that every part of the motherboard is functioning correctly before you can plug in your components. This guide will teach you how to test a motherboard with a multimeter.

When to Test the Motherboard with the Multimeter?

If the motherboard is not working as it used to, there will be a lot of problems. This problem can cause a lot of damage to your computer. You should find out if there is a problem with the motherboard before it causes a big problem. You can check it with a multimeter. The multimeter is a very useful tool for checking the condition of the motherboard. It can help you to test the motherboard and find out whether there is any problem with it or not. You should have a multimeter at home so that you can check the motherboard easily.

Test the Motherboard with the Multimeter with these simple steps;

For DC Voltages

  1. To test the DC voltages turn the multimeter up to 20V DC and attach the 20-pin ATX connector. Ensure that the computer is connected and running on an AC power supply. Probe the backside of the connector using the multimeter’s black probe and set the probe with the 15, 16, or 17th pin of the connector.
  2. With the other probe of the multimeter probe the 9th and 14th pins and check the reading. Pin 9 should be at 5V and pin 14 should be between 3 and 5 Volts, any reading above or below this point means that there are some discrepancies in the power supply unit.
  3. Use the red probe again to check the 8th pin which should give a reading above 2.5 Volts. This indicates that the computer is ready to start. Resetting the meter would make the reading drop to zero and then back up when the computer restarts.

For Open and/or Short Circuits

The power supply unit is the heart of the computer. It is the main component of the motherboard that supplies power to the rest of the components in the computer. The power supply unit needs to be checked for short circuits. If you find a short circuit, you can get the motherboard repaired.

  1. To check the motherboard, first, disconnect all cables and unplug the power supply unit. Then, put a multimeter on the power supply unit. The power supply unit should have two wires that connect to the motherboard. One of the wires is the ground wire, while the other wire is the power supply.
  2. Unplug the computer from AC power and let it rest for a while. Then set the multimeter to the lowest Ohm setting (i.e. 200 Ohms) and connect the probes to the surface of the PC. The reading should remain the same.
  3. Remove the 21-pin ATX connector from the motherboard, but keep the black probe on the metal surface. The red probe should be used to check the DC connector’s black wire pins.
  4. The black probe on the surface and the red one to check the reading of the colored wire pins on the DC connector. The reading should be 50 V or above.
  5. Disconnect the CPU from the motherboard and use the red probe to check the GND pins. Probe the 3rd, 5th, 7th, 13th, 15th, 16th, and 17th pin. The reading should get to zero, any other reading would indicate that the connector is faulty.

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