An image forming device management system includes a plurality of image forming devices, a central service station which provides a maintenance service for the image forming devices, and a communication control unit which is connected to each of the image forming devices by a signal line, the communication control unit connecting one of the image forming devices to the central service station via a communication network. In the system, each of the image forming devices includes a message unit which outputs a signal line separation message when the image forming device has no signal from the central service station or the communication control unit over a predetermined period.