How to Test a Motherboard With a Multimeter- Guide by Computer Expert

How to Test a Motherboard With a Multimeter

The motherboard is indeed the mother of all boards! It is comparable to the brain because of it single-
handedly takes care of all the functions of a CPU.

It is designed in such a way that it does not need any wires to make sense of the circuitry. However,
every now and then, a need for testing or troubleshooting the motherboard. This is when a
multimeter comes handy. It will help you test almost all the circuits, especially when something’s
wrong. Troubleshooting is an important part of owning a system or any electrical device, for that
matter. A multimeter is an excellent tool for the same.

How to Test a Motherboard With a Multimeter?

Let’s dig deeper into this and figure out how to use a multimeter while testing your motherboard.

For short circuits

We are going to talk about testing for short circuits first because it is a common problem and may
happen when there’s a surge of electricity.

  • Switch the computer off and unplug it.
  • Wait for several minutes so that it cools off completely and has no charge.
  • Bring out your multimeter and adjust it to the lowest setting. This is usually 200 Ohm. To
    bring the meter to zero, you have to touch both the leads together. Once you do that, test it
    with the chassis to ensure that it is still zero.
  • Open your computer to find the motherboard. Remove the ATX connector from it.
  • The red lead goes to the PSU’s AC ground pin while the black lead stays on the chassis. The
    black wire pins should be on the DC connector. Even at this point, all the readings should be
    zero.
  • Now, ensuring that the black lead stays in its place, use the red lead to check all the colored
    wires. 50 or more is normal. Anything below 50 is a matter of concern.
  • You can also check further to find faults. Remove the motherboard completely from your
    system. Refer to the ATX 20-pin chart to find the pin numbers on your motherboard. Use the
    red lead to test each of the GND pins. 3, 5, 7, 13, 15, 16, and 17 must be zero. If you see any
    other reading, there’s a problem.

For DC voltages

The steps to check DC voltages are slightly different. Here they are:

  • The 20-pin ATX needs to be connected, and in this case, the computer has to be connected
    to power.
  • The multimeter setting should be at 20V DC.
  • Use the black multimeter probe to probe the connector on the back. It should be in contact
    with 15, 16, and 17 pins.
  • The red probe, on the other hand, should probe 9 and 14. Pin 9 should read 5 V, and pin 14
    Should read between 3 and 5 V.
  • Switch the PC on. If the readings drop to zero, everything is fine. If not, you have issues to
    fix.
  • Now, you need the red probe again. Use it to check pin 8. It should ideally be more than 2.5
    V. Press reset and see if the reading goes down to zero and then goes back up. If it doesn’t,
    you need help.

It may seem daunting, but the process of testing a motherboard with a multimeter is not all that
bad. There are just a few steps to follow and voila! You will know if there are any errors to fix or if
your motherboard is in pristine condition.

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