Crossover Pca (Nt6M48Xx) Replacement; Power Supply (Nt6M71Xx) Replacement - Nortel DMS-10 Series Quick Reference Manual

56K Crossover PCA Replacement
Procedure (NT6M48xx)
Procedure 8
56K Crossover PCA (NT6M48xx) replacement
Step
CAUTION
Since all BMC PCAs are static sensitive, be careful when
handling them. Wear a wrist grounding strap when working
with the BMC.
WARNING
Since the BMC is powered up during this procedure,
observe all safety procedures for operations on live equip-
ment.
1 Make sure no polling is occurring. Wait for a low traffic period,
if possible, to execute the steps in this procedure.
2 Remove the slotted screws that fasten the outer edges of the B
rear panel assembly to the cabinet.
3
Remove the front panel of the A chassis. Put the two panels in
a safe place to prevent bending and scratching.
4 Remove the power from the 56K Crossover PCA first by dis-
connecting plug (P1). Then remove the other cables.
Note: Verify the cable markings (identification) or attach labels to the
cables when removing them to facilitate replacement in the correct posi-
tions.
Alarms may also activate and the BMC status panel lights will
all be OFF. This is normal. Silence the alarm at the switching
system and go to step 5.
5 Remove the screws that fasten the 56K Crossover PCA. Gently
remove the PCA from its mounting position.
6
Mount the replacement PCA in the vacated position.
Note: When replacing the screws, align carefully before tightening to
avoid stripping. Tighten the screws, alternating until all are equally
tight. Do not "cinch down" any one screw until all are properly aligned;
no binding or force needed to turn.
7
Reattach any cables removed in step 4 in reverse order.
Note: Verify the cable markings (identification) or attach labels to the
cables for correct positioning.
WARNING
Incorrect positioning of cables will cause alarms and com-
munication problems.
Description
BMC II AMAT Quick Reference Guide
51