Four–channel communication circuit pack 149
DPP Card Replacement Guide BCS35 and up
Procedure 16–1
Four–Channel Comm circuit pack replacement
Step
Description
Notes
CAUTION
Since all DPP circuit packs are static sensitive, be
careful when handling them.
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 a grounding strap.
WARNING
Since the DPP is powered up during this procedure,
observe all safety procedures for operations on live
equipment.
1
Wait for a low traffic period, if
possible.
Make sure no polling is
occurring.
2
Notify technical assistance personnel
of the temporary loss of MMI and
polling links.
Polling link for DPP systems
without 56K polling is routed
through the P/A Comm circuit
pack. DPP systems with 56K
polling use a path through the
56K Xovr to the 56K
Connector circuit pack.
3
Remove the slotted screws on the
outer edges of the rear panel
assembly to the cabinet.
4
Remove the rear panel of the A
chassis.
5
Pull the rear panel away from the
cabinet. Remove the front panel of
the A chassis to improve convection
cooling, if necessary.
Put the two panels in a safe
place to prevent bending and
scratching.
