Northern Telecom BCS35 Replacement Manual page 53

Error Control II and Error Control II Jumper circuit packs 37
Procedure 5–1
Replacing Error control II circuit pack (A5)
Step Description
1 Remove both front panels (A and B)
of the DPP.
2 Pull the front panels free of the
chassis.
3 Make sure the DPP is in B ONLY
processor mode.
4 On the Error Control II Jumper circuit
pack in the B chassis (B5), pull the
toggle switch outward and lift the
switch to the up position.
5 Power down the A chassis by
pressing down the red rocker switch
to 0.
6 Replace the Error Control II circuit
pack in the A chassis.
CAUTION
Wear a wrist grounding strap when working with the
DPP. Jacks at the lower right of the Rover Interface
panel (B chassis) and the lower right of the Switch and
Status Panel (A chassis) are provided to accept the
banana plug connection on the end of the grounding
strap.
1
(continued)
DPP Card Replacement Guide BCS35 and up
Notes
Loosen the four captive screws on the
left and right hand sides of the
chassis. See Figure 5–1.
Put the panels in a safe place to avoid
scratching and bending.
Make the A/B select switch indicate the
B processor.
Set the O/P select switch to O.
Turn mode insert key and release.
Switch serves a dual function. First,
remove the B chassis power–feed
from the Error Control II circuit pack in
the A chassis. The toggle locks the
error control functions to the B
chassis.
Slot 5.