A displacement system for a hard disk drive comprising a driving circuit and first and second displacement elements. A receptacle includes insulation sleeves and conductive contacts in openings of receptacle housings, and plugs include a ferrule assembled bodies which are composed of an insulation ferrule which holds an optical fiber and a conductive cylindrical member which holds the ferrule and to which a wire is assembled, in an opening of the plug housing. A method is also disclosed for contacting emergency services upon determination of an emergency situation. Further, by using the conductive layer as a power source layer, the capacity of supply of power to an IC chip can be improved.