Mcu: Serial connection closed / Timeout on connect / Wait for identify_response

Knowledge Base
1

mcu: Serial connection closed / Timeout on connect / Wait for identify_response

Background

The printer-board / MCU did not respond to the connection attempt of the Klipper Host until finally the serial connection timed out and was closed. Typically these 3 errors will go hand in hand in the klippy.log

Reasons

  • Hardware issues between the board and the SBC, e.g. USB port, USB cable etc
  • Wrong parameters during make menuconfig when building the firmware for the board
  • Firmware not correctly flashed to the board
  • Dead board

Potential solutions

  • Follow How-To Trouble-Shoot → Connection Problems to the printer board → 3. Check Linux Diagnostic Messages to check if and how the board registers on the Host
    • If it registers but does not identify as Klipper then most like the firmware is not correctly flashed
    • If dmesg shows simply nothing, then either the USB connection is faulty or even the board may be dead
  • Check and verify the parameters used during make menuconfig
  • Repeat the flashing process
  • Check with ls /dev/serial/by-id/* for the presence of the board and compare the output to the settings [mcu] block