Answer:
1: Check the income feed the power switch on the controller is open;
2: The former beam on the sensor sensing the distance is too short, not close paper; sensor sensing the distance is too long, then stop, and post-contrast volumes. Method: Micro-adjust sensor behind a small screw, counterclockwise rotation of regulation: induction distance shorter, and vice versa variable length;
3: After the beam on the sensor sensing the distance is too long, not feed; sensor sensing the distance is too short, then stop. Method: Micro-adjust sensor behind a small screw, counterclockwise rotation of regulation: induction distance shorter, and vice versa variable length;
4: controller failure, need of replacement.