Microwave Light is Flickering, Flashing, or Making Noise (3 Fixes!)

Is it normal for a microwave interior light to flicker? If you’ve noticed this phenomenon occurring in your microwave, you’ll want to read the rest of this article.

There are a number of possible causes for a flickering interior microwave light.

  1. The light bulb may be loose.
  2. The switch that activates the microwave light could be faulty.
  3. The contents of the microwave could be causing an arcing phenomenon.

Keep reading below to determine the cause of your flickering microwave light, and follow along till the end to get learn about some potential solutions to the problem.

is it normal for a microwave interior light to flicker

Is it normal for a microwave interior light to flicker?

The microwave oven light should be steady when the door is opened, or the microwave oven is switched on and cooking.

It is not normal for it to flicker on and off.

If the microwave is connected to a shared circuit with some lights, you may experience the dimming of the lights (not the interior microwave light) that share the same circuit as the microwave when it is switched on and running.

If you experience this phenomenon, it’s a sign that the circuit is nearly overloaded, and you should consider installing the microwave on a dedicated circuit.

If the interior microwave light is flickering, however, you have another problem on your hands, and it could be a cause for concern.

Why does the microwave light flicker ON and OFF?

There are 3 likely reasons why your microwave’s interior light might flicker when the microwave is in use.

The light bulb might be loose

If the light bulb might is loosely seated in the holder or the connecting wires are loose or broken, you may experience some flickering of the interior microwave light. A loose bulb is the simplest possible fix for this issue, as all you’ll need to do is screw it back in tightly.

If the connecting wires are loose or broken, on the other hand, it may be a more significant job. Read on below to learn how to deal with this issue.

The switch that activates the light might be faulty

Most microwave interior lights activate automatically when the door is closed, and the microwave oven is powered on. However, some older models may have a manual light switch. If this is the case for your appliance, and you begin to experience flickering, there may be an issue with this switch.

The problem would likely be a poor connection or a short circuit. In either case, it’s probably best to replace the switch. This is a job for an experienced electrician, and in some cases, it may be more cost-effective to simply purchase a new microwave oven.

is it normal for a microwave interior light to flicker

The contents of the microwave are causing arcing

If the contents of the microwave contain metallic elements such as aluminum, the flickering light you’re witnessing could be a result of the dangerous microwave phenomenon known as arcing.

Arcing is caused by microwaves produced by the appliance when they react with metallic elements such as aluminum, gold, or other basic metals. The reaction results in sparks that emit from the metallic material and can appear to an outside observer as a flickering light. If powerful enough, this reaction can cause the microwave to catch on fire if there are other flammable materials in and around the appliance.

Always turn off an arcing microwave to avoid damage to the oven and to limit the risk of fire. Despite the danger, however, it is highly unlikely that an arcing microwave will actually explode.

You may also be interested in: What causes a microwave display to flicker and what you can do about it

How to fix a flickering microwave interior light?

Fixing the microwave interior light obviously requires an understanding of the cause of the problem. Read the sections below to identify the recommended fix for each of the following causes.

Loose light bulb

Check the wire connections to the light bulb and make sure that they are firmly connected to the light build holder and intact with no damage.

Confirm that the light bulb is firmly seated in the bulb holder. If you find the bulb to be loose or improperly placed in the holder, then simply use your hand to tighten the bulb into place. Of course, may sure the microwave is unplugged before doing so.

If the microswitch and light bulb wiring and connections are intact and you still have a flickering light bulb, then you might have a fault with the microwave’s control board. You’ll also want to look into this if you notice the microwave display light flickering.

If this is the case, you may want to contact a technician or begin looking for a new microwave oven.

is it normal for a microwave interior light to flicker?

Faulty switch

Confirm that the electrical wires connecting to the door switch are firm and that there is no breakage in the individual wires.

You can carefully inspect the individual wires connecting to the switch to confirm that they are intact.

Check that the mechanism connecting the door to the micro-switch is intact, not broken, and aligns properly so that it opens and closes the switch contacts cleanly when the door is opened and closed, respectively.

Next, check if the micro-switch works as expected.

When the door is closed, the micro switch should cleanly break the electrical circuit – so there should be no continuity when taking measurements with a digital meter.

Similarly, when the door is open, the meter should display continuity.

If the tests show that the micro-switch is not working as expected, then arrange to get a replacement switch for your microwave. Watch the video below to learn how to install a new door switch.


To fix a microwave that’s been arcing, start by unplugging it and examining the interior for any visible signs of damage, such as loose metal or burnt spots.

Clean the inside thoroughly, removing any food debris or grease buildup that may be causing the arcing. Arcing isn’t a sign of any mechanical or electrical problem with your microwave. Instead, it’s a reaction caused by basic metals that have somehow made their way into the microwave.

To fix this issue, you simply need to remove these metals. If you continue using a microwave with these types of metals, over time, the waveguide cover could become damaged.

If the issue persists, inspect the waveguide cover for signs of damage and replace it if necessary.

Final Thoughts

A flickering microwave interior light can be annoying.

Though in some cases, it may not affect your cooking, it should be attended to and fixed.

Fortunately, most of the solutions to this problem are easy to fix. Try out some of the methods listed in this article, and get back to whipping up tasty treats for you and your family.

Why a microwave light flickers when opening the door?

Depending on the model of the microwave, it might be that the door microswitch is malfunctioning hence the flicker.

In some cases, the switch can be loose, and fixing it properly solves the problem. In other cases, a replacement switch may be required.

Why the microwave light may not be working?

If the light does not work (always confirm that the microwave is switched on), confirm that the bulb is securely fitted in the bulb holder. A loosely fitted bulb can stop it from working.

If this does not fix it, it is possible that the bulb has burned out and needs to be replaced. Though not so common, it is also possible that the bulb holder may be damaged or there is a loosely connected wire.

What to do when you notice the microwave flashing and buzzing?

If the microwave is flashing and buzzing, there may be arcing. Quickly cut power to the microwave, then open it and inspect the interior for metals such as aluminum foil or silverware.

What to do when you notice dimming or flickering lights while running your microwave?

Turn off the microwave, then check to see what else is on the circuit your microwave is using. You may have an overloaded circuit. Move some of the other appliances to another circuit and see if that fixes the issue.

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