No movement on any axis on Ender 3 Pro I've printed the dog that came on the SD card of my new Ender 3 pro, and everything worked great.  Today, I turned on the unit and plugged in a Raspberry PI Zero to the Ender's USB port.  The rPi is running the latest version of OctoPrint.
Now, when I try to Auto home, I hear a very brief sound of a motor staring to move on an axis, and then the Ender halts.  I've power cycled it several times.  When I trying to use the panel on the Ender to move on any axis the same thing happens: it sounds like it's starting to move, and then never actually tries to move again until after I power cycle.  This is the same no mater which axis I try to move.
I've reinstalled the lated firmware on the Ender.  I've opened up the machine to make sure that all of the cables are attaches to the motherboard.  I've checked the actuation of the stopper switches and unplugged the switch and motor connectors.
I upgraded to the latest firmware, and now everything works again.