Nortel DMS-10 Series Installation, Operation And Maintenance Manual page 641

Power Supply Replacement (NT6M71AB)
If maintenance requires the removal of a power supply, using the following
procedure. The only tool needed is a small flat-blade screwdriver. If
necessary, have replacement fuses on hand.
Procedure 6-47
Power supply (NT6M71AB) replacement
Step Description
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 equipment.
167
Remove the front panel of the BMC.
If you are changing the A power supply remove only the A panel.
If changing the B power supply, remove both the A and B front panels, this allows access
to the Switch and Status Panel.
Loosen the four captive screws on the left and right sides of the front panel; carefully
remove the front panel. Put it in a safe place to avoid damage.
168
Put the processors into an Only mode. At the Switch and Status Panel of the BMC:
a. Press the A/B Select Switch to:
A - If you are changing out the B power supply
or
B - If you are changing out the A power supply
b. Press the O/P Mode Select Switch to O.
c. Turn the Mode Switch to the right and release.
BMC II BISYNC Operation, Administration, and Maintenance Guide BMCB001 and up
Section 060-INDP-610 Maintenance Procedures Guide 6-203
(Sheet 1 of 4)