Your Microwave Is Sparking Inside or Outside

If your microwave begins producing sparks, this could either be a sign of a malfunction or an indication that it's being used incorrectly. Here we explain the various possible causes for this issue.

THE POTENTIAL CAUSES FOR THIS PROBLEM:

• The mica sheet is dirty

• The internal cavity and seal are damaged

• The door and its grid are damaged

• The roller ring has stains on it

WARNING
We recommend adopting a very cautious and safety-conscious approach if you need to take your microwave apart at any point.
Microwave ovens produce powerful electrical discharges that can potentially be fatal.
Never test and use a multimeter on the appliance with it still plugged into the mains. The voltages on either the magnetron, transformer or capacitor may be too high for the multimeter to cope with.
Even when unplugged, the capacitor inside the microwave oven can still produce power electrical discharges.
We therefore recommend you leave the appliance to discharge for at least one day before taking it apart.
When you first open the microwave up, make sure you short circuit the capacitor using a pair of electrically insulated pliers (with the appliance unplugged from the mains of course).
We also recommend wearing a pair of electrically insulated gloves to ensure you are able to work in complete safety.
Carrying out repairs on a microwave oven requires a very careful and safety conscious approach. SOS Accessoire cannot be held responsible for any accidents that may occur.

The mica sheet is dirty

All microwave ovens are fitted with a part referred to as a mica sheet. This is a small cardboard or plastic covered sheet that will normally be located on the ceiling or right-hand wall of the appliance's internal cavity. It serves to both distribute the electromagnetic waves inside the interior of the microwave and protect the appliance's internal components. If your microwave's mica sheet has food remnants stuck to it, this can cause sparks to be emitted. A convenient and easy way to solve this is by gently cleaning the sheet with a slightly soapy damp sponge. Leave your microwave's door open afterwards to allow it to dry. If the sparks still continue to be produced even after cleaning it in this way, you will need to examine the sheet to see if it's damaged. Any cracks, holes or burns you find could be due to repeated and persistent sparking. In which case, it is advisable to replace the mica sheet. You can either purchase this component as a stand-alone, compatible part or buy a piece of universal mica sheet that you can cut to measure and fit in your microwave oven.

Purshase a microwave mica sheet

The internal cavity and seal are damaged

If part of the microwave is scratched or damaged, exposing the bare metal, this can cause sparks to be emitted. Once you've located the site of any damage that's occurred, there's a simple tip you can use to repair it. Cover the scratch with several coats of nail varnish, preferably the translucent kind. Give it plenty of time to dry properly before using the appliance again. The microwave's internal cavity and door seal need to be kept clean. If food debris is allowed to dry and carbonise, this will create sparks and damage the cavity.

The door and its grid are damaged

The door is fitted with a metallic grid that acts as a Faraday cage. It both keeps the microwaves inside the oven and allows you see into the interior. If this grid gets damaged, sparks will be produced. If this is the case with your appliance, you will need to replace the door. Make sure your carefully follow the safety instructions provided at the beginning of this article when carrying out this operation. To avoid these kinds of problems occurring, we recommend regularly cleaning the door of your microwave.

The roller ring has stains on it

The roller ring supports the turntable. If sparks are being produced underneath your microwave's turntable, this will almost certainly be due to stains or food debris on the roller ring. You can try cleaning it to see if that makes a difference. If it's broken or damaged, however, you will need to replace it.