I cleaned the coils and the freezer isn't freezing, refrigerator is only cool.

A component in the defroster is going and/or gone and needs to be replaced.

Please explain better about your problem. We have no idea what you are talking about. What is buzzing and is your freezer iced up? Explain in detain; we have no crystal ball to be able to see your unit. DrTom4444

Don't know about the person above, but I am having the same problem. The buzzing sound is very difficult to pinpoint the location of, but it is an electronic type of buzz. It seems to be coming from the freezer side of the unit, as opposed to the fridge side, but I can't be certain. Every minute or two, it buzzes for about 2 seconds. This has been going on for a couple of weeks, and I've been ignoring it. However, now the freezer is not running cold enough, and things are beginning to melt. It seems that it could be stuck in defrost mode, since it is running and is cold, but not cold enough. The freezer is not iced up. I will follow up with a better location on the buzz, if I get one.