Originally Posted by btuinstra
How would I verify the voltage when the microwave is running?
Normally you would use a digital volt meter and probe the same outlet that the microwave is running off of by inserting the meter probes into the socket between the hot and common. If it's not an outlet but a hard wired connection then you would remove the wire nuts and probe the wires directly. Black wire is hot and white wire is common.
I do have to add to this one point. If you have to ask this question, then you may want to find someone more electrically savvy to do the check for you. If done wrong you can hurt yourself.