In plain words
A balance visit follows a settled order. The technician first checks for a broken spring, displaced cable, binding or track damage; once safe to move, the door is run through a powered cycle, then released to repeat the movement by hand, separating the motor from the door. Springs, cables, drums, rollers, hinges and track are inspected before anything changes. Adjustment comes next, in small steps with a test after each one, until the door holds at every height and sits level. Finally the opener is reconnected, its settings reviewed against the newly balanced door, and the reversing safety tests run while you watch.