No buttons. No help menu. Just text fields with labels like NCU_Serial_Override and Laser_Trim_Level .
And on the machine’s touch panel, in glowing green letters, a final message appeared: canon service tool v4720
CAUSE: Stepper motor driver failure (Thermal). EFFECT: Carriage rail warp, 0.02mm. CORRECTION: Not field-serviceable. No buttons
On it: Canon Service Tool v4720.exe .