The first time my microwave started sparking, I nearly jumped out of my skin. One second, I was heating up leftovers, and the next, there was a mini fireworks show inside my microwave. My first thought? “Oh great, I’ve broken it.” My second thought? “Do I need to run before this thing explodes?”
If you’re in the same boat—standing in front of your microwave, staring at it like it just betrayed you—take a deep breath. Microwaves can spark for a few different (and usually fixable) reasons. Most of the time, it’s NOT broken, and you WON’T have to buy a new one.
Let’s go through the possible causes one by one, and I’ll show you exactly how to fix them.
Step 1: Stop the Microwave and Unplug It
If your microwave is currently sparking, STOP IT IMMEDIATELY.
✅ Press the stop button.
✅ Unplug the microwave from the wall.
✅ If you see smoke, leave the door closed until it stops.
💡 Why? Microwaves don’t usually catch fire, but sparks can lead to scorch marks or permanent damage if left unchecked. Stopping it right away prevents further issues.
Now that the microwave is safely off, let’s figure out what went wrong.
Step 2: Check for Metal Inside (The Most Common Cause!)
This might sound obvious, but double-check that you didn’t accidentally put metal inside the microwave.
🔹 Did you reheat something in a takeout container with a metal handle?
🔹 Did you accidentally leave a fork or spoon on a plate?
🔹 Is your plate or bowl edged with gold or silver trim?
Even tiny bits of metal can cause major sparks because microwaves reflect off metal surfaces, creating an electric arc.
🛠 The Fix:
1️⃣ Remove any metal objects.
2️⃣ If you see scorch marks inside, wipe them down with a damp cloth.
3️⃣ Try running the microwave empty for 5-10 seconds. If there are no sparks, you found the culprit!
💡 Pro Tip: Some paper towels and takeout containers have hidden metal bits. Always check before microwaving!
Step 3: Look at the Waveguide Cover (It Might Be Dirty or Damaged!)
Now, this is something I didn’t even know existed until my microwave started acting up. The waveguide cover is a small, rectangular piece (usually plastic or mica) inside the microwave that directs energy to your food. If it’s greasy, food-splattered, or burnt, it can cause sparking.
How to Check and Clean the Waveguide Cover:
1️⃣ Look inside your microwave—usually on the right or top side, you’ll see a small panel (this is the waveguide cover).
2️⃣ If it’s covered in grease or food splatters, grab a damp cloth and wipe it clean.
3️⃣ If it’s burnt, cracked, or has a hole in it, you’ll need to replace it.
🛠 Replacing the Waveguide Cover:
✅ You can find replacements online for less than $10.
✅ Just pop out the old one and slide the new one in place—no tools needed!
💡 Pro Tip: To prevent this issue in the future, always cover your food when microwaving. Grease buildup is the #1 reason waveguide covers get damaged!
Step 4: Check the Rack or Shelf (If Your Microwave Has One)
Some microwaves have metal racks or removable shelves. If these aren’t positioned correctly, they can cause sparking.
How to Fix It:
✅ Make sure the metal rack isn’t touching the sides of the microwave.
✅ If the rack has burn marks, remove it and see if the sparking stops.
✅ If you don’t use the rack, just take it out completely!
💡 Pro Tip: If you use the metal rack often, clean it with vinegar and baking soda to remove residue that can cause sparks.
Step 5: Inspect the Turntable and Roller Ring
Sometimes, the problem isn’t inside the microwave chamber—it’s underneath your plate.
🔹 Check the turntable (the glass plate) for cracks or chips.
🔹 Remove the roller ring (the small plastic ring with wheels) and clean it.
🔹 Make sure nothing is stuck underneath—crumbs, grease, or even a misplaced piece of foil can cause sparking.
🛠 The Fix:
✅ Wash the turntable and roller ring with warm, soapy water.
✅ Wipe down the inside of the microwave, making sure no debris is left behind.
✅ Put everything back and do a test run with a cup of water for 30 seconds.
💡 Pro Tip: Never put a cracked turntable back in the microwave. Even small chips can cause uneven heating (or worse, more sparking).
Step 6: Look for Exposed or Burnt Internal Components
If you’ve checked everything else and your microwave still sparks, it could be an issue with internal components like:
🔸 Burnt magnetron – The part that generates microwave energy.
🔸 Damaged diode – Helps convert power to the right voltage.
🔸 Faulty capacitor – Stores and releases energy for the microwave.
Unfortunately, these aren’t DIY fixes. If your microwave is old (5+ years) and has internal damage, it might be time for a replacement.
🛠 The Fix:
✅ If you see burn marks or exposed wiring inside the microwave, stop using it.
✅ Call a technician if the microwave is still under warranty.
✅ If it’s an older model, consider replacing it—repairs can sometimes cost more than a new microwave.
Once you’ve cleaned everything and removed any problem items, it’s time for a test run.
✅ Fill a microwave-safe cup with water.
✅ Place it inside and run the microwave on high for 30 seconds.
✅ Watch closely—if no sparks appear, you’ve fixed the problem! 🎉
If sparking still happens, it’s likely an internal issue, and you might need to replace the unit.
I know how scary it is when your microwave suddenly starts sparking—it freaked me out too! But the good news is, most of the time, it’s an easy fix.
✔️ Check for metal inside the microwave.
✔️ Clean or replace the waveguide cover.
✔️ Remove the metal rack if it’s touching the sides.
✔️ Inspect the turntable for cracks or debris.
✔️ If it’s still sparking, it might be time for a new microwave.
Now that you know what to do, next time this happens, you won’t panic—you’ll be prepared. 😉
