A system includes a control module, a network interface module, and a charging module. The power source controller turns off the first power source switch when the power source voltage detector detects a voltage of a specific value or less. The power-source control section executes a power supply to the tuner, the demodulation section, the AV-data processing section and the microcomputer, in response to the power-supply instruction signal. A coil spring acts between wall and plate urging it towards wall. The method comprises activating a secondary cell configured by a network of the wireless communication system, performing a random access procedure for the activated secondary cell, and when the secondary cell is deactivated during the random access procedure, continuously performing the random access procedure. Even when the wiring width of the conductor wiring is decreased, the conductor wiring can be adhered to the wiring board firmly.