Optical disc drive with a system behavior detection module

An optical disc drive includes a servo system and a system behavior detection module. The system behavior detection module includes a controller and a signal feeding unit coupled to the controller and the servo system. The controller is operable in a detection mode and in a normal operation mode. In the detection mode, the controller enables the signal feeding unit so as to introduce an exciting signal into the servo system. In the normal operation mode, the controller disables the signal feeding unit so as to inhibit introduction of the exciting signal into the servo system.