Hi @busy12
It could be any number of things in the microwave oven, that is causing it to trip the breaker e.g. faulty HV transformer, faulty magnetron, faulty turntable motor, faulty door interlocks, pinched wiring etc.
''Microwave ovens are not the safest appliance to work on unless you know what you're doing. The HV capacitor in the oven can store >5000V DC for months, even if the power has been disconnected for this length of time. ***This amount of voltage can seriously injure you.*** The HV capacitor needs to be correctly discharged as soon as it can be accessed after removing the cover from the oven and before commencing any further work inside the oven.''[br]
You will need to have a digital multimeter and the wiring diagram for the oven to help find out what's wrong. The part number for the wiring diagram is GE 31-20925 but unfortunately I cannot find it online. GE used to place the diagram inside the oven along one side next to the circuit components, but I don't know if this is applicable to your model. If it is not there, the best I can suggest is that you [https://www.allrepairmanuals.com/ge-microwave-oven.htm?model_number=JVM1650BBC|purchase] it as it will save a lot of time trying to locate the problem.
Here's a link to a parts [https://www.partselect.com/Models/JVM1650BB007/Parts/?SearchTerm=mini%20manual|supplier] that may also help. If a part needs replacing, use the supplier linked to find out the ''manufacturer's part number'' for the faulty part and then use that number when searching online to find suppliers that suit you best.