E677 The external controller is faulty 0001 When a controller for other model is connected. 0002 The condition of initializing communication is faulty. 0101 The external controller fan is faulty. 0004 Come-off detection of the external controller (The external controller fails to detect a connection while the power is ON, even though the controller properly detected it when the power was turned ON). 0008 The communication of the external controller is faulty (When the communication from the external is faulty while communication to the external controller is established). 0080 The communication to a printer is faulty after the external controller properly started up.