Embodiments of the present invention are directed to merchandise security systems and methods for displaying and protecting an article of merchandise from theft. In one example, the system includes a sensor configured to be secured to the article of merchandise, wherein the sensor includes alarming circuitry. The system also includes a tether comprising a pair of conductors electrically connected to the alarming circuitry, wherein the pair of conductors is configured to transfer power to the sensor and/or to the article of merchandise. In response to power ceasing to be transferred, the alarming circuitry is configured to monitor an electrical signal transmitted through the pair of conductors in order to determine whether the tether has been cut or removed from the sensor.