Cover,Insulator

If you notice arcing sparks and charred marks on the inside right of the microwave, usually near the top of the silvery, flat waveguide cover (the insulator part mentioned here), it's simple to fix. Thoroughly clean the inside of the microwave and scrub the charring off of the wall as much as possible. Remove the four little white pegs ho ... Read more lding the waveguide cover to the side of the microwave and remove the part, then carefully clean under/around it. Replace with the new waveguide cover when dry and you're good to go! ----I have fixed two microwaves this way -- the part is incredibly cheap, so it's worth a try! This problem happens more frequently when the inside of the microwave is covered in food residue.