Northern Telecom DMS-100 Series Maintenance Manual page 226

7-12 Routine maintenance
Procedure 7-4
Replacing the fan behind the rover interface panel
Step Description
1 Request a polling session from Collector
personnel.
2 Remove the front panel on the A chassis.
See Figure 7-2.
3 At the Switch and Status Panel:
a. Press the A/B processor. Select
Switch to show the same as the
processor with the operational fan.
b. Make the O/P processor Mode
Select Switch O.
c. Turn the Mode Switch to the right.
4 Remove the Rover Interface panel from the
B chassis.
Remove the two slotted screws from the
panel to take it out of position.
297-1001-537 Standard 01.02 December 1993
Since all circuit assemblies, disk drives, and other
hardware in the DPP are static sensitive, be cautious.
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.
(continued)
Notes
Explain that maintenance activity is
scheduled at the DPP as a precaution.
Loosen the four captive screws on the left
and right of the front panel and carefully
remove it. Put it in a safe place to avoid
damage.
Note: Skip this step if the processor mode
is already AO.
See Figure 7-1.
Make the A processor the ONLY processor.
Turn it 45 degrees to the right and release.
The Rover Interface panel is in the same
position as the Switch and Status Panel on
the A chassis. Hold this panel tightly since
it comes loose. The ground jack wire
connections and the Rover terminal wire
connections are mounted on the back of the
panel. Save the screws to use later.