Nortel DMS-10 Series Quick Reference Manual page 64

54 Power Supply Replacement Procedure (NT6M71xx)
Procedure 9
Power Supply (NT6M71xx) replacement
Step
4 Enter the following commands to write the value 00 in the
DRAM memory address 2204 for the off-line DSI/TEC PCAs:
>DOS S TECMAINT MEMWRITE 1 2204 00 (cr)
>DOS S TECMAINT MEMWRITE 2 2204 00 (cr)
5 Power down the faulty power supply.
Remove power from the standby chassis by operation of the +8
V dc red rocker switch on the power supply.
Remove the -48 V dc source for the standby processor chassis
at the main fuse panel; disk drive in this chassis is now dis-
abled.
WARNING
Removal of the incorrect -48 V dc source can cause loss of
AMA.
Note: This step will cause an alarm.
6 Remove the three connector plugs from the front of the power
supply. Squeeze the side release clips and pull down gently;
fold the cables back out of the way.
7 Loosen the slotted-head captive screw at the bottom of the
power supply. Gently pull the power supply out of the chassis.
Make sure the three connectors (and cables) are out of the way
during removal of the power supply unit.
8 Install the replacement power supply. Make sure all cables and
connectors are out of the way of the insertion path. Make sure
the proper fuses are installed in the replacement power supply.
9
Gently slide the power supply into position until it is fully
seated. Tighten the slotted captive screw until snugly in place;
do not bear down.
If any resistance, remove the power supply and check for
obstructions. Remove the obstructions and reinsert the power
supply.
10 Reconnect the three connectors removed in step 5 during the
removal phase. Connect as follows:
Pwr Sup Conn.
a. J8 to P8
b. J9 to P9
c. J10 to P10
11
Restore the -48 V dc power source at the main fuse panel.
297-6201-500 BMCA001 and up
Description
Standard 02.01 July 1997