| 摘要 |
PURPOSE:To shorten a trouble investigation time and to perform temporary repairing by inserting an integrated circuit element of the same type in the socket provided to the upper part of the integrated circuit element mounted on a printed circuit board. CONSTITUTION:When an integrated circuit element 1a of the same type as the integrated circuit element 1 mounted on a printed circuit board is inserted in the socket 2 provided to the upper part of said element 1, the signals of the input and output pins (1, 5, 6) of the element 1 are propagated to the pins (1, 5, 6) of the element 1a through the pins (3, 7, 8) of the socket 2. Further, the output pin (2) of the signal gating the input and output signals of the element 1a is connected to the pin (e) of the socket 2 and, for example, when a logical signal (a) is inputted from the pin (2), the try state gate circuit 10 mounted on the printed circuit board becomes a high impedance state and the output signal of the element 1 is closed and the output of the try state gate circuit 10a of the element 1a becomes effective in place to be propagated to the output pin (1) and the element 1a can be put to practical use in place of the element 1 and a trouble element can be judged within a short time. |
