To reset a Classic FCU, you would hold in on the joystick while you plug the battery in. The screen will display DEFT until the joystick is released and all settings will revert back to factory default.To reset a Mini FCU, hold back on the trigger while plugging in the battery and keep the trigger held for longer than 5 seconds before releasing. The settings will reset to factory defaults and it will enter the programing main menu upon releasing the trigger.