What is the problem?
Since today, OctoPrint can't connect to the printer (MonoPrice Select Mini V2) via USB cable.
Yesterday was working fine. I didn't print anything yesterday, but I tried to use the command M300 to play some tone.
What did you already try to solve it?
Changed USB cable, OctoPrint safe mode, restarted the Raspberry Pi multiple times and the printer, disabled every plugin installed.
The problem is that the Raspberry didn't recognize the serial port.
Then, following this post, I enabled again the serial port using raspi-config. Since then, OctoPrint recognize the serial port but can't still connect to the printer.
The serial port recognized by the system is the ttyS0.
Additional information about your setup
OctoPrint version: 1.4.0
OctoPi version: 0.17.0
Raspberry Pi Zero W
Printer: MonoPrice Select Mini V2
Printer firmware: 41
Malyan/Monoprice Connection Fix: installed version 0.1.3
Recently I didn't install any Debian updates.