Solution: "MCU connection error" since at least April 30th due to Debian 11 update

[hcet14]

Basic Information:

Printer Model:
MCU / Printerboard:
klippy.log

No issue, maybe info.

Ender 3 S1 - No USB ID

An even better fix was found in the Klipper discord by xF4m3 and XeroX: In case you still have this issue after updating today, i found this fix in the voron discord klipper channel (its a pinned message there) EDIT: Latest Debian 11 changed by intention or accident by-id and by-path mapping in systemd. This fixes the issue when klipper is not able to connect after recent update of Apr 29th 2023. Make sure you’re root or using sudo -s before. Reboot is mandatory. sed -i ‘/^SUBSYSTEMS==“pci”…

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[evandene]

@Ender 3 S1 - No USB ID

sed -i ‘/^SUBSYSTEMS==“pci”…

sed -i ‘/^SUBSYSTEMS==“pci”… results in: sed: -e expression #1, char 1: unknown command: `▒’
And yes I gave the command as root

[Sineos]

See Debian Bullseye Bug causing Klipper to no longer find the printer board - #8