Last updated: 2026-05-01
📡
Microwave Sparking Inside
Arcing or sparks visible inside the microwave cavity
50%
50% chance this is caused by:
Damaged waveguide cover or metal debris inside
🔧 The Exact Part You Need
Total parts cost: $8. Same-day shipping available on most items.
🔨 Tools You'll Need
Easy · 5-10 minutes
Parts: $8 vs $$100-500 to replace
📋 Step-by-Step Instructions
1
Unplug the microwave
2
Look inside the cavity for any metal fragments or food debris
3
Check the waveguide cover (small mica sheet on the right wall)
4
If it's burned, charred, or has holes, replace it
5
Peel off the old cover and stick the new one in place
6
Test with a cup of water
Other Microwave Problems
Frequently Asked Questions
How much does it cost to fix a microwave that's sparking inside?
The part costs about $8. If you do it yourself, that's your total cost. A professional service call would add $100-200 in labor, bringing the total to $158.
How long does this microwave repair take?
This repair is rated "easy" and typically takes 5-10 minutes. The most time-consuming part is usually accessing the component, not the actual swap.
What if this isn't the problem?
Our diagnosis is 50% likely based on the symptom you described. If replacing this part doesn't fix it, the next most common cause for "arcing or sparks visible inside the microwave cavity" would be related to the wiring harness or control board. In that case, consider calling a professional.
Should I just replace my microwave instead?
A new microwave costs $100-500. If yours is well under 7-10 years old, a $8 repair is far more cost-effective. If it's near end-of-life and has had multiple issues, replacement starts making more sense.