With the unfortunate photos of the H3 fire I was reminded of a small piece inside the microwave / convection oven. This piece of card board with a silver colored coating can develop carbon deposits which can cause arcing and even a fire! Since reading the warning online we checked our unit and guess what ....our unit was carbonized and glowing during the defrost cycle We immediately ordered a replacement...under $3 and resolved the problem. Take a few seconds and check it out. Any discoloring or carbon is not normal...replace immediately. I believe the website is www.parts store.com or something close to that. Ken & Ellen