Exit/Entry Points:
Numbered circles are used to move from page to page within a flow chart. In the example
shown, exits to point ‘2’ appear on both pages 6 and 9; entry point ‘3’ is located on page 7.
Each circle has its destination (or origin) page number(s) noted beside it.
2
PAGE F6, 9
3
PAGE F7
3 . 5 1
Board Swapping to Confirm Fault
Board swapping can be used to confirm a faulty board diagnosis when the suspect board is
duplicated in the system. This applies in particular to exchange line boards, station interface
boards, power failure boards and 2 wire internal extension interface boards when used.
Take the suspect board and swap this board with an identical board. If this yields the same
fault, the faulty board has been located. The fault will follow the faulty board.
129
ISSUE 1