What is the cardboard cover in my microwave for?
What is the cover for?
The cover covers your microwave's waveguide. The waveguide is an electronic part that guides the energy of the microwaves to your food. The cover has a coating that protects it against high temperatures. Damaging or removing the cover may cause short circuits in your microwave, because splashing food could end up in the electronic parts.
The cover broke. Now what?
If the cover was damaged, short circuits in your microwave might occur. Due to fire hazard, it's not safe to use your microwave. Unplug it and buy a new cover. You can order the cover via your microwave's manufacturer or via a local component store. Make sure you know your microwave's brand and serial number, so you can order the right cover. You can find this information on your microwave's label. You can usually find this on the interior of the door or at the back of the appliance.