Peter V Georgetown , KY September 29, 2015 Arcing from the magnetron intermittantly I searched the web and it seemed that many people had a similar problem when gunk got on the waveguide plate/cover. When I removed the cover, one of the plastic latches broke so rather than just trying to clean the plate, I had to order a new one. The new one arrived in just a couple of days, I put the plate on and at least for the last few days, no more arcing. <$10 fix for my over the stove microwave. Read More... 3 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes Tools: Screwdrivers