Compared to the cost of a new stove or another household appliance, microwaves are relatively inexpensive. It can be more time-consuming and frustrating to fix a microwave than it is worth. \
As a general rule, you should perhaps try to fix a microwave if it is less than five years old and especially if it is still under warranty. But if the microwave is older than this, you should probably replace it because other things could start to go wrong with it after you fix the first problem. \