Addressing a Sparking Microwave

Appliance Express
October 5, 2020
Microwave Repair

While all appliances in your kitchen have a use, none get more daily use than your microwave. Whether it is heating up water because the tea kettle takes too long or warming up a quick midnight snack before bed, it is the fast and easy option for heating food. However, we tend to forget that the microwave can be one of the most dangerous appliances in a kitchen too, but you will be reminded of it if it ever starts throwing off sparks.

A sparking microwave, whether they are inside the appliance or outside of it, is a big problem. It means something is wrong, yes, but those sparks are also a huge fire hazard. Once it starts happening, you should immediately stop using your microwave until it is repaired for your safety.

Before You Begin: A Warning

If there is one appliance that you should really not attempt repair on, it is the microwave. Even minimum DIY skill can get you by in some other appliances, but not in a microwave, it requires a skill, but more importantly, appropriate caution.

The issue is that while you will likely begin this repair by disconnecting the electricity, as you would with any other appliance, a microwave will still hold a charge. The capacitors can hold a lethal charge even when disconnected from the electricity. They must be properly discharged before you can safely address microwave problems. This can be done by short-circuiting the capacitor with an electrically insulated screwdriver or simply waiting a day or more for the charge to dissipate on its own. Even then, a microwave repair should be done with electrically insulated gloves, just in case, so you can avoid a pretty nasty shock.

While it is still strongly recommended that you call a professional for microwave repair, if you do take the proper precautions, it is a simple appliance to diagnose once you are inside.

What Causes Microwave Sparking?

If your microwave is throwing off sparks, there are a few causes of it. You will need to look at the location of the sparks and any other symptoms in order to quickly diagnose what you should do.

Check For Metal

If you notice sparking inside your microwave, one of the first checks – because it is so simple – should be to check for metal. Maybe you left a fork in your leftovers, but the metal in your microwave is not always so obvious. For example, one of the most frustrating causes of sparking is for those that clean their microwave with steel wool. The steel wool, during the scrubbing process, can leave behind small metal shavings. These, while near-microscopic, will still cause sparking when the microwave runs.

The fix for this is actually quite simple, you just need to wipe down the microwave to remove any small bits of metal. If you turn on the microwave again, the sparks will be a good indicator of where you missed any metal.

Dirty Wave Guide

The waveguide, or mica sheet, is a small square located on the side of most microwaves, but sometimes on the ceiling of them. This serves as a way to direct the electromagnetic waves produced by the microwave towards the center where your food is. However, it can be a finicky piece. If it is damaged, then it will throw off sparks and need to be replaced. However, even if it is merely dirty with food particles, it may still spark during use. If you notice sparking, you should first try cleaning it. However, if you see any cracks or even large spots of the scorching, it should be replaced to avoid sparking or any other problems.

Door Grid Damage

If your microwave has a crack in the door glass, you will likely see sparks either inside or outside the microwave. The metal mesh inside the door glass serves as a Faraday cage. It keeps the electromagnetic waves inside the microwave while still allowing you to see somewhat inside the glass. Yet, if your microwave door has endured some damage, the cage malfunctions a bit and results in sparks.

If your door has any damage, you will want to have the door replaced and this should fix the issue immediately.

Damaged Internal Cavity

The internal cavity of your microwave is made of metal. So why does it not throw off sparks like the appliance would if you left a piece of tin foil in there? Well, the answer is simple it is covered with a protective coating that prevents that. However, if your microwave does start throwing off sparks and you notice portions of the internal cavity are worn or scorched, then you have found your issue. The protective coating has been worn, scrapped, or chipped away and now your microwave will continue to throw sparks until this issue is fixed. You can find the appropriate coating at the hardware store or online, but nail varnish will work in a pinch. Be sure to let any applied coating dry properly first.

Microwave — Repair or Replace

With any substantial issues with a microwave, the question will always undoubtedly come up. Should you repair it or is it easier to just replace the microwave? For many, their microwave was a small investment, well below $100 in price. For others, their microwave is more costly and even serves as a range vent over their stove.

As the cause of sparks in your microwave can be rather innocent and easily fixed, it is really just better to repair the issue. However, if your microwave is ancient and quite cheap, a replacement can be a quick fix for you, especially if you feel more comfortable calling a professional to fix it and it serves as just a microwave in your home.

Need Help?

Do you have a malfunctioning microwave or other appliance that you need to be repaired? We can help with that. Contact us today to see what Appliance Express can do to help. Let our professionals solve your appliance problems quickly so you can get them back up and running.


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