Yep, the microwave is what I like to use as a starting point in the troubleshooting. The microwaves in RV's are usually wired on their own separate circuit than any other outlet....as you can usually note on the distribution panel like in the pic below:
If the microwave is receiving power, then that usually tells me to start the troubleshooting inside the RV...as power is reaching the RV from outside. You can usually work forward from the RV's electrical circuit panel to the GFCI's to the outlets themselves
However if the microwave is not getting power, then that alerts me to start the troubleshooting from the source of 120 volt power (campground pedestal, home outlet, generator, etc) and then go forward.