Help "mcu 'mcu': Unable to connect" and have tried all troubleshooting steps I could find

Basic Information:

Printer Model:Ender 3 V2
MCU / Printerboard: STM32F103/ V4.2.2
Host / SBC: Raspberry Pi 4 model B
klippy.log

Klipper log following print failure and some attempted fixes:

klippy.log (134.8 KB)

new klipper log:

klippy.log (79.6 KB)

Describe your issue:

Just recently built and customized a new Ender 3 V2 and was able to go through multiple short calibration prints and steps with no issues. When I went to print a longer 20+ hour long print the print stopped and then the pi and printer stopped being able to communicate with each other. Here are all the steps I have tried so far:

  • flashed a new MCU on the printer
  • updated klipper
  • tried to use both by-id and by-path for MCU path
  • replaced usb cable with shorter cable with a ferrite core
  • made sure the 5V on the usb cable was covered with electrical tape and not providing power
  • checked for voltage on the motherboard
  • reinstalled original firmware on printer and confirmed it installed and screen went to normal ender 3v2 interface
  • checked all connections and disconnected all unnecessary connections on the motherboard
  • completely reinstalled klipper and made new printer firmware

I have attached the klipper.log from before the pi reinstall and the klipper.log from after