To easily specify a system bus short circuit position in a mobile communication base station device.

A master panel 11 first sequentially resets slave panels 12-1, 12-2, 12-4 and 12-5, decides whether a system bus short circuit is eliminated or not at each time, and outputs a short circuit alarm in a panel of a corresponding slave panel to an operation center 16 if the system bus short circuit is eliminated. If the system bus short circuit is not eliminated, the master panel then sequentially disconnects the system buses 13-2 to 13-5, decides whether the system bus short circuit is eliminated or not at each time, and outputs a system bus short circuit alarm of the corresponding system bus to the center 16 if the system bus short circuit is eliminated. If the system bus short circuit is not eliminated at a time point when all the system buses 13-2 to 13-5 are all disconnected, the panel 11 outputs a service stop alarm to the center 16.