How To Test Laptop Charger with Multimeter

If you want to use your laptop to its full potential, you’ll need a dependable power source. The charger for your laptop is critical for providing enough energy to keep it running properly – but what happens when the charge doesn’t appear to be doing anything? Understanding how and why your laptop may not always charge is difficult without specialized knowledge, but testing the laptop charger with a multimeter is quite simple. In this blog post, we’ll go over how to test a laptop charger with a multimeter to ensure you get the best performance out of your device. So let’s get this party started!

How To Test Laptop Charger With Multimeter

Most Common Causes of a Faulty Laptop Charger

Worn-out Cable:

Over time, laptop chargers can suffer wear and tear from being plugged in and unplugged frequently. This can cause the cable to become frayed or loose, resulting in a faulty charger.

Broken Connector:

The connector, the small piece of plastic that connects the charger cable to your laptop, can also become worn out or broken over time, causing it to no longer make an effective connection with your device.

Faulty Power Adapter:

The power adapter is responsible for converting wall outlet power into the correct power level output that is used by your laptop. A faulty adapter will not be able to provide sufficient energy for your laptop, resulting in a dead battery or no power at all.


Overheating is one of the most common causes of laptop charger failure. This can be caused by an overworked adapter, dusty ports, or simply using the charger for too long. If your charger is getting hot to the touch, it’s time to replace it with a new one.

Poor Quality Charger:

Cheap or knockoff laptop chargers are often made with inferior components and materials, making them much more prone to failure than official-brand ones. Only purchase genuine chargers from authorized retailers to ensure your device’s safe and reliable use.

By understanding what causes a faulty laptop charger, you can avoid costly repairs and ensure your device runs smoothly. If your laptop charger is not working as expected, take a closer look at the cable, connector, power adapter, and overall product quality to determine if it needs replacement.

How To Test Laptop Charger with Multimeter?

Testing a laptop charger with a multimeter is an essential step in determining if the charger is working correctly. It can also be used to troubleshoot any problems you may be having with your laptop battery or power supply.

  • Gather the necessary materials: a multimeter, laptop charger, and AC adapter.
  • Connect the multimeter to the AC adapter and set it up according to its instructions.
  • Make sure that the polarity settings on the multimeter are correct for your laptop charger (positive and negative terminals).
  • Turn on the power switch located at the back of the laptop charger.
  • Move to test mode on your multimeter and check whether or not there is any current flowing through the circuit by connecting both positive and negative probes to each side of your laptop charger plug. The measuring device should show some voltage level if electricity flows through it.
  • Once you have established a current flowing, use the multimeter to check the voltage output. It should match up with the voltage rating of your laptop charger (usually between 19V and 20V).
  • If everything looks good, turn off the power switch on your laptop charger and disconnect it from the AC adapter.

The laptop charger has been successfully tested, and you are now ready to enjoy all its benefits! Testing your laptop charger with a multimeter can help identify any issues needing resolution before using it with your laptop or other devices. If you encounter any problems during testing, contact a qualified electrician for further assistance as soon as possible.

Frequently Asked Questions:

Can I test my laptop’s charger with a multimeter?

Yes, you can use a multimeter to see if your laptop’s charger is functioning correctly. You must ensure that the voltage of the power supply matches the voltage specified in your laptop’s user manual. It would help if you also looked for any continuity issues between the charger’s pins and the corresponding ports on your laptop.

How do I set up my multimeter to test my laptop’s charger?

First, make sure your multimeter is connected correctly with leads that are compatible with it and your laptop. Then, on your digital multimeter, choose an appropriate setting. Set the multimeter to measure AC voltage if your laptop charger is barrel type and DC volts if it is brick type. Connect the multimeter’s leads to the corresponding pins on your laptop’s charger. Finally, consult your laptop’s user manual to determine which voltage setting you should be looking for.

What should I do if my laptop’s charger fails the test?

If your laptop’s charger does not meet the required voltage or has any continuity issues, it is defective and must be replaced to ensure proper operation. To avoid further problems, you are strongly advised to use an original charger. It would be beneficial if you also inspected the power supply cable, as it could be defective and require replacement. Finally, you should consider having your laptop repaired by a professional technician if there are any underlying issues with its internal components.


Finally, while testing laptop chargers with a multimeter is simple, it does necessitate careful attention and safety precautions. Before testing the laptop charger, carefully follow the instructions in this article and turn off all power sources. This ensures your safety and aids in the diagnosis of any problems with the charger. If you are unsure or uncomfortable at any point during the testing process, seek the advice of an experienced professional. You can test a laptop charger safely and without incident if you have the proper knowledge and resources.

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