Our coach has an inverter, which is a device to convert battery power into 110 volt electricity. It also manages charging the battery from the campground pedestal power.

One day the Magnum inverter panel in our coach reported an “Unknown Fault”:

The fault and voltage display kept changing, with garbage values:

Time to apply an old computer maxim: “when in doubt, reboot.” I looked up the instructions on how to reboot the inverter, in its manual under “Performing an Inverter Reset”:

Here’s the Magnum inverter unit in the basement; in our 2017 Tiffin Allegro Bus 40SP motorhome it is mounted on the ceiling of the frontmost main storage compartment, on the driver side:

So I just needed to turn off the power at the pedestal, then hold down the button (below the green light in that photo) for 15 seconds. That did the trick.