3D Printer Not Extruding Due to Extruder Motor Failure

Extruder motor failure is confirmed when the control board sends extrusion commands, but the motor shaft remains stationary or emits a grinding sound without engaging the filament. Verify this by observing the gear on the extruder motor while commanding an extrusion movement via the printer interface; if the motor does not rotate or makes a clicking noise despite the hotend reaching the target temperature, the motor or its driver is likely faulty.