Technical data

9-8
Field Replacable Units
9
Fan Tray Removal/Replacement
Three DC-powered fans (four fans in the dual 9-slot chassis)
provide forced-air cooling for the VMEmodules and mass storage
drives in the VME card cage. The fans (Figure 5-4) are mounted in
a tray below the card cage. If a failure occurs in any of the fans, the
tray is replaced as a unit.
The suggested procedure for removal and replacement of the
cooling fan tray is as follows:
Removal
1. Switch the power supply of the affected system to
STANDBY
and disconnect the system from the AC or DC power source:
– If the power supply is an AC unit, unplug the power cord
from the AC outlet.
– If the power supply is a DC unit, turn off the -48Vdc power
source and unclamp the DC leads from the terminal block
on the power supply.
2. Remove the front bezel, if installed.
3. At the front corners of the fan tray, loosen the two quarter-
turn fasteners that hold the tray in the chassis.
4. Slide the fan tray out.
Replacement
1. Slide the fan tray back into the chassis. Use firm steady
pressure to seat the connectors properly.
2. Tighten the two quarter-turn fasteners that hold the tray in
the chassis.
3. Reinstall the front bezel, if the installation includes one.
4. Reconnect the system to the AC or DC power source.