AT&T 7400B Plus User Manual page 27

DEFINITY Communications System
7400B Plus Data Module
User´s Guide
Caution: Disconnect all cables and telephone cords attached at
the rear of the unit. Failure to disconnect all cables and
cords at this point could result in permanent damage
to the 7400B Plus.
Remove the top access panel of the 7400B Plus as follows:
1
(See Figure 2-4.)
While applying a gentle lifting pressure at the rear edge
a
of the access panel, insert the tip of a ball-point pen or
other suitable device into each of the two tab-lock holes
in the rear panel to release the locking tabs.
Lift and remove the access panel.
b
If a ROM board is installed just inside the access opening of
2
the 7400B Plus, grasp the edges of the ROM board inside the
access opening and lift the board out of its socket.
Locate the 8-position DIP-switch on the main circuit board,
3
approximately in the center of the area exposed by the access
opening.
Set the appropriate positions of this DIP-switch as shown in
4
the Table 2-1.
If a ROM board was removed in step 2, reinsert the board
5
into its connector.
Replace the access panel by placing it into position and
6
pressing down at the rear edge to engage the locking tabs.
CHAPTER 2: INSTALLATION
Page 2-13