Another "MCU Unable to Connect" Issue

General Discussion
1

Basic Information:

Printer Model: Tevo Tornado (Upgraded)
MCU / Printerboard: MKS Robin Nano V1.2
Fluidd/Moonraker/Klipper
klippy.log

printer.cfg (2.6 KB)

Made Upgrades to my Tevo Tornado printer replacing the old MKS GEN L board with a MKS Robin Nano V1.2. I loaded the board with Marlin 2.1.2.7 setting the script for the old TEVO Tornado components only changing MKS Robin Nano board and pin settings. All checked out well and flashed MKS Robin.. Did the same with raspi-config, Klipper.bin

After installing Fluidd, Moonraker and Klipper via Kiauh (using WIFI connection) I can connect via WIFI to fluidd on my desktop … when I check out the host in Fluidd it shows everything running with the exception to Klipper-MCU being “dead”

Now after going on over a month now … I have repeatedly uninstalled Fluidd, Moonraker and Klipper and reinstalled from some issues of corrupt files … never sorted any of this out on the MCU issue.

SO? I am at a total loss at this time getting my printer’s MCU connected researched everything I could research or think of researching .. Now I have to talk to the experts.

Screenshot 2026-05-25 104039
Screenshot 2026-05-25 104039295×322 8.49 KB

klippy (4).log (322.2 KB)

2

First try a new USB cable from the Pi to the printer mainboard.

Next open fluid and go to the [System] tab and find the “devices” button.

image
image1967×861 75.7 KB

Click it, select serial and click Refresh.

Is your mcu listed? You have is as /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0 in your configuration. Does the ID match?

3

Hi Cardoc ..

Yes it’s listed in the path-by_id (see attached)

Serial
Serial594×670 30 KB

4

Just to double check .. I ran “serial/by-id/”

pi@TevoTornado:~ $ ls -l /dev/serial/by-id/
total 0
lrwxrwxrwx 1 root root 13 May 25 17:48 usb-1a86_USB_Serial-if00-port0 → ../../ttyUSB0

I did try two other USB cables to see if there was a bad connection, without any luck.