I'm happy I found this site. I was wondering if anyone could help me out here. I've had a Hamilton Beach microwave model #87108 for about a year or so. Up until now it's worked great and I am sure to keep it regularly cleaned, now just the other day I cleaned it for a family get together I was about to have...I cleaned it with a hot soapy dish rag then rinse thoroughly and allowed to dry just as I normally do...Later that evening I heated something up and it worked like a charm, after taking the item out(which by the way had NO metal of any sort) my niece hit the start button and it began to spark and pop. We immediately turned it off and examined it to see what could have possibly caused it, the microwave was completely empty and dry. My husband has since been trying to figure out why it is doing it and is about to fork out money for a new one, I'm wondering if this one can be saved?
The only other thing you might try is to is to clean the wave guide. On some it's behind a cover you can remove with a screwdriver and some it just fits in a bracket on the wall of the interior. You need to clean both sides and look for burnt looking spots. You can replace it at an appliance parts store. You can cut them to fit.
Don't run it without food or liquid, the microwaves need somewhere to go, otherwise they will find something like a little grease, as stated above, like under the wave guide cover, or worse, destroying the mag tube.
Very confused about sparks in Microwave 
