| Listening for noises |
It is normal for a microwave to produce noise during its regular operation. A change in the type of noise produced is most likely indicative of some type of maintenance that needs to be performed.
The appearance of a grinding, squealing, or scraping sound could mean you need a belt replaced or that a motor is in need of lubrication. Performing minor maintenance tasks now, such as lubricating a motor and replacing a belt, can prevent having to conduct even more costly repairs in the future.