How to Perform a Lamp Test to Verify Power

If the light comes on, then the plug works

By
Tim Fisher
Photo of Tim Fisher, Lifewire GM and Writer
Tim Fisher
Senior Vice President & Group General Manager, Tech & Sustainability
  • Emporia State University
Tim Fisher has more than 30 years' of professional technology experience. He's been writing about tech for more than two decades and serves as the VP and General Manager of Lifewire.
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Updated on August 24, 2022

What to Know

  • Wall outlet: Unplug all devices from outlet > plug in lamp you know works. If lamp turns on, power is good.
  • Power strip: Unplug all devices > plug working lamp into each power strip outlet one-by-one and test for power.
  • If power strip has no power, replace with another. If outlet has no power, troubleshoot or call electrician.

This article explains how to verify that power is being provided to an outlet or power strip by using a "lamp test" when a multimeter isn't available.

How to Perform a Lamp Test to Verify Power

Follow these instruction to perform a lamp test. It should take just a few minutes to complete.

This is just a working/not-working test, so it can't determine if voltage is a bit low or high, something that might make little difference to a light bulb but be important to your computer. If this is a concern, testing an outlet with a multimeter is a better idea.

  1. Unplug your PC, monitor, or other device from the wall outlet and plug in a small lamp or other device that you know is working fine.

    If the lamp comes on, then you know your power from the wall is good.

  2. If you're using a power strip, follow the same directions as in the last step for your power strip.

  3. Unplug your computer, monitor, and any other device from the outlets on the power strip and perform the same "lamp test" on the power strip outlets to see if they are functioning properly.

    Make sure that the power switch on the power strip is flipped on!

  4. If any of the wall outlets aren't providing power, troubleshoot this issue or call an electrician.

    As an immediate solution, you could move your PC to an area where the wall outlets are working properly.

    If your power strip isn't working (even just one outlet), replace it; we keep a list of the best surge protectors here.

If both the power strip and the wall outlet are providing power, but your computer still doesn't turn on (and especially if it doesn't turn on when plugged into a different, known-to-work plug), consider testing your PC's power supply.

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