Removing and Installing SCbus Interface Boards
1. Normally you should disconnect the AC power cord from the AC outlet and disconnect the optional battery
back-up assembly from the power supply; however, when necessary, you can remove or install some printed
wiring boards in an operating system. If you must do this, connect one end of a standard telephone handset
coil cord to the precharge port on the power supply. During step 5, you will connect the other end of this coil
cord to the precharge jack on the printed wiring board.
CAUTION
If the board you need to install or remove does not include a precharge jack, you must not install or
remove it in a powered system.
2. Install your static discharge wrist strap on your bare wrist; adjust it for a snug fit. Be sure that the strap is
touching bare skin and is not isolated by clothing. Connect the wrist strap cord between the wrist strap and an
AC or earth ground
NOTE: With the common equipment in the installed position, the ground lug on the side of the cabinet is an
appropriate grounding point since it should have a heavy ground wire connected between it and a good
earth ground.
3. Each new board is supplied in a static protection bag for safe keeping. When you are ready to install the
board, remove it from its static protection bag. Conversely, when you remove a board from the cabinet,
immediately place it in a static protection bag.
4. Locate the proper board slot. (Most line, station, and special purpose interface boards use the universal slots.)
When installing the first SCbus board, use the 6th (top) universal slot to insure a proper connection to the PC
power cable. Any subsequent SCbus boards installed do not require the PC power connection.
5. If you are removing or installing the board in an operating system, connect the free end of the precharge cord
that you installed in step 1 to the precharge jack on the line board.
6. If you are removing boards from the cabinet, remove the retaining hardware, pull the boards toward you until
their board edge connectors separate from the cabinet’s backplane connection, and slide the boards free of the
cabinet.
7. To install boards, orient them with the left and right guides in cabinet board cage. and press the boards firmly
until their board edge connectors properly mate with the connection on the cabinet’s backplane.
8. Make a final inspection to
ensure that all boards are
oriented correctly and mated
properly.
9. Install and tighten the
supplied screws to secure the
installed boards to the board
cage.
10. If you are installing line
boards, note that each board
includes a ferrite collar. Snap
the ferrite collar around the
cable to provide protection
against radio frequency
interference.
4 Removing And Installing Circuit Boards
IMI89–313
Installing The SCbus Interface Board
Dedicated Auxiliary Board Slot
Dedicated CPU Board Slot
Universal Board Slots 1 through 6
(Used for Line or Station Boards)
Typical Circuit Board
Pre-charge Port Location
Power Supply Assembly
Pre-charge Port Location
Locating Circuit Boards
