My Jenn-Air Microwave at the beginning operated normally with a sound of an exhaust fan running

I noticed that exhaust fan sound stopped one day, however microwave continued to heat food normally

HOWEVER, now when I heat foods for 4+ minutes I run the risk of the unit shutting down completely and acting like it has no power, completely unresponsive.

After about 1 hour unit will come back to life requesting the user to set the time.

I'm thinking that fan sound i'm now NOT HEARING, is an exhaust fan that exhausts mositure, and that moisture is building up in the cook area, and activating a sensor causing the unit to shut down out of safety.

What do you think and how do you think I can fix it?

Thanks for your help.

Brent

Yea, that sounds like a good place to start to me. Would you say this job is one for the homeowner or technician? My microwave is above my stove. To access the fan motor will I have to remove the microwave from the wall or can I get to it through the inside of the microwave?