MMU Upgrade / Reboots from any command
I bought a MK2S pre-assembled last year, and received the MMU kit seperately. I have just done the upgrade and have followed all of the steps accurately. I have upgraded drivers and firmware successfully.
Now trying to calibrate, and the first step of loading the filament fails. As soon as you select any of the 4 extruders, the firmware reboots to the home screen with no activity on the extruders. After pre-heating the nozzle, I can manually move Extruder 1; however if I try to manually change Extruder number, it also just reboots. If I manually select "Extruder 2/3/4" it reboots, and when i manually move the Extruder channel, it just moves Extruder 1 again.
Video :
I am very confident all of the steps of the MMU upgrade instructions (including notes in the comments) have been very closely followed, and are assembled correct. All of the firmware and drivers have also been installed correctly, and updated correctly.
I've already spoken to the online Prusa chat/support, but they were unable to help. At their request, I have emailed support with further information to hopefully find an answer to this.
In my opinion it's a firmware issue, as I can manually jump the steppers and make them work, and the hot end and heat bed works fine from the Preheat menus.
I'll update this forum post when we have a solution.