1, the frame tongue door does not return to the initial position but is open, this time we must adjust the frame spring force or the replacement spring.

2, the belt although in place, but the sensor does not detect the signal, this time we have to check into the belt and the sensor into place, if the failure of timely repair and replacement.

3, packing belt thickness clearance adjustment too small, spring elasticity is too strong, this time we only need to adjust the thickness of the packing belt gap.