Therefore the property owner must deal with the problems as they arise other than waiting for a major breakdown in which case an emergency handling is called for. Do a simple checklist of the things that tend to go wrong. First ensure that the cord is properly plugged in and that there is a functional power source.
Sometimes it is a question of switching everything off, waiting for the motor to cool down and then testing it all again. Look at the sensor beam in order to ensure that it is accurately lined up with its target according to the specifications that have been set out by the manufacturer. It is essential that there are no blockages or barriers to the sensors which are almost always on the knee-level for overhead garage doors.