A computer unit includes computer components each having a processor and a computer component controller for controlling the operations of the computer components by communicating a control signal with the computer components through a radio transmission path. Another computer unit has a similar configuration. At an instruction from an external control terminal which has recognized the fault of another computer component controller provided for the another computer unit, the computer component controller concurrently controls the operations of computer components provided for the another computer unit by communicating a control signal through a radio transmission path.