Just wondering if my one EZ Robot ultrasonic sensor with built in voltage regulator, 3 wire connector,is still working. Is the red light supposed to be on all the time or only when a digital port is on?mine has no lights and nothing on the ARC sonar window. PORT on or off same thing,nothing.Could be bad regulator,possibly works if I remove and just add external 5v battery power?I liked this one because of the v regulator built in.