Nortel North American DMS-100 Instruction Manual page 71

Repairing and replacing NT3X90AA cooling units
At the front of the cooling unit
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10
11
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DMS-100 Family NA100 Trouble Locating and Clearing Procedures Volume 2 of 2 LET0015 and up
Trouble locating and clearing procedures (continued)
If your company procedures
do not direct you to do repairs
Remove the screws that secure the side rail covers to the frame.
Remove the eight screws that secure the brackets to the sides of the cooling
unit. To remove the screws, use a 5/16-inch ratchet and extension.
WARNING
Loss of frame cooling
Removal of the cooling unit for an extended period of time
can cause the equipment in the frame to overheat.
Ease the cooling unit toward you until it is half-way out of the frame.
Inspect the fans in the cooling unit. Note any fans that do not work.
Do
step 71
1-55
(continued)