How to Fix a Sparking Microwave Oven
Heres’s how to do it:
Along the side (or in the back in some models) is a rectangular piece that usually looks like a metal plate. It’s called a “wave guide cover,” and it’s screwed into the microwave wall over an opening.
This wave guide cover is to protect the inside of your microwave from stray bits of food or moisture. When food becomes stuck to it, even a tiny speck can sometimes make it spark and even send spark showers throughout the oven.
Your mission: Remove the cover, clean it thoroughly, clean around the area where it fits, and replace it.
First, unplug the microwave. Put it where there is plenty of light and remove the screws that hold the wave guide cover in place. Place them where they won’t get lost and carefully remove the wave guide cover. You may have to use a little force to get it loose, especially if the wall has food or grease on it. Don’t use anything sharp to pry it loose. A butter knife or the edge of a plastic lid will do.
Using a soft cloth and plain water, gently clean the wave guide cover. If something is stuck to it, use your fingernail or a piece of plastic mesh to remove it. Be very careful as the material is somewhat fragile. It’s ok to let the cover get wet, but be sure it’s completely dry before replacing it.
Clean the area around the opening that was covered by the wave guide cover very carefully, making sure to not get any moisture or food inside the opening.
When you’re sure both are completely clean and dry, replace the cover, plug in the microwave and try it. Most of the time, this will do the trick. If, however, it doesn’t and you’re still getting spark showers inside the microwave oven, you’ll need to replace the wave guide cover.
Write down the exact make, model and anything else you can find on your microwave oven, then call around for a store that will sell you a replacement. That may be a lot easier said than done because most people don’t repair microwaves, they just toss them out and buy new ones. However, the part is inexpensive and can get you several more years of use from your oven – well worth the effort.
If you can’t find the wave guide cover locally, try the internet. I found one easily and had it shipped to me for about a fifth the cost of a new microwave.