| 摘要 |
PURPOSE:To enable easy discrimination of whether a trouble has occurred in a circuit board or outside thereof, by directly connecting the input and output of the circuit board to each other to compare its output and input signals with each other by an operation control unit in the board when the trouble has occurred. CONSTITUTION:When a trouble has taken place, the output jack 41 and input jack 31 of a printed circuit board 1 are connected to each other through relaying plugs 16. At that time, a control signal for the trouble is generated by an operation control unit 2 in the board 1. Feedback to the operation control unit 2 is effected through the output jack 41, the relaying plugs 16 and the input jack 31. The control signal and a feedback signal are compared with each other about each bit by the operation control unit 2. If the contents of all the bits coincide with each other, the circuit board 2 is regarded as normal. If the contents of all the bits do not coincide with each other, the circuit board is regarded as defective. |
