Northern Telecom BCS35 Replacement Manual page 133

Procedure 13–1
Replacing Disk XOVR circuit pack
Step Description
5 Pull the rear panel away from the
cabinet. Remove the front panel of
the chassis to improve cooling, if
necessary.
6 Loosen the 2 screws at the top of the
hinged card panel and the screw at
the bottom of the hinged card panel.
7 First remove power cable (J4), then
any cables and screws connected to
the suspected circuit pack.
8 Mount the replacement assembly in
the vacated position and reconnect
any cables removed in step 7 in
reverse order. Verify the repair by
switching disk modes back to
5
PRIME.
Enter:
>DISK MODE xx (cr)
where:
xx = disk mode = AP = A PRIME
Proper response =
DISK MODE: AP
DISK MODE: BP
9 Lift the hinged circuit assembly gate
back to its vertical position and tighten
the (3) screws loosened in step 4.
10 Route all wires and cables to avoid
pinching or crimping when the rear
panel is reinstalled.
Disk Crossover and Controller circuit packs 117
2
3,4
(at the terminal)
= BP = B PRIME
or
6
(continued)
DPP Card Replacement Guide BCS35 and up
Notes
Put the two panels in a safe
place to prevent bending and
scratching.
Let it swing slowly down from
the top until it rests.
Gently pull the suspect
assembly loose from its
mounting position.
If the replacement XOVR
circuit pack solves the
problem, the DPP will begin a
disk copy that may take
several hours, depending on
how much data and how large
the disks are.
(from disk mode AO)
(from disk mode BO)
Remove the insulating
material, if used.