If your extruder motor is not turning when you issue it manual commands via a host software, there are a few simple things that you should check.
- Is the extruder motor plugged into the E0 Stepper Motor Port (For the RAMBo) / E Stepper Motor Port (For the Mini-RAMBo)
- Is the hot end heated to the target temperature? The firmware has a safety feature that does not allow the extruder to extrude filament if the temperature is not above 150C.
- Is the set screw in the hobbed drive roller tightened against the flat in the stepper motor shaft? If it is not, this could allow the stepper motor to turn but not engage the hobbed drive roller, preventing filament from being extruded.