What is the problem?
Serial connection to a Anycubic Mega S could not be etablished anymore. (will try a downgrade back but before I like to ask if somebody still know this issue)
What did you already try to solve it?
Changing USB cable
Switched everything off and on
Have you tried running in safe mode?
Did running in safe mode solve the problem?
serial log ->
2021-01-20 20:26:23,413 - Enabling serial logging
2021-01-20 20:26:26,691 - Changing monitoring state from "Offline" to "Opening serial connection"
2021-01-20 20:26:26,713 - Connecting to port /dev/ttyUSB0, baudrate 115200
2021-01-20 20:26:26,783 - Changing monitoring state from "Opening serial connection" to "Connecting"
2021-01-20 20:26:26,789 - Connected to: Serial<id=0xa4a69630, open=True>(port='/dev/ttyUSB0', baudrate=115200, bytesize=8, parity='N', stopbits=1, timeout=10.0, xonxoff=False, rtscts=False, dsrdtr=False), starting monitor
2021-01-20 20:26:26,829 - Send: N0 M110 N0125
2021-01-20 20:26:26,833 - Send: N0 M110 N0125
2021-01-20 20:26:35,872 - Recv: áNp|ÿ0}HHÎ(0} qfñJpON6J=hZ>|Y,]^a~6¨HªXñJð~¨5A@6M7¨øa
2021-01-20 20:26:35,890 - Recv:
2021-01-20 20:26:35,894 - Recv: á^e6jO>ìJª_YÁ¬aJ%è}ÁMhp|}>Xe6H.lp|4]êXñJJXñzÂHH6fñJ8J8HJÆJêYÙaz$~H^ì}Ù$p|4
2021-01-20 20:27:06,261 - No answer from the printer within the connection timeout, trying another hello
2021-01-20 20:27:06,282 - Send: N0 M110 N0*125
2021-01-20 20:27:16,316 - There was a timeout while trying to connect to the printer
2021-01-20 20:27:16,338 - Changing monitoring state from "Connecting" to "Offline"
2021-01-20 20:27:16,341 - Connection closed, closing down monitor
Additional information about your setup
OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible
OctoPI 1.5.3, Anycubic Mega S Knutwurst Firmware, Raspberry PI 4 2 Gb Ram
Printer beeps to confirm connection attempt but it does not succeed.
Perhaps related to this but did not know. Updated and wont connect to Printer