6.5 Replacing the DECmpp 12000/Sx DPU Fan Tray
6.5 Replacing the DECmpp 12000/Sx DPU Fan Tray
Take the following steps to replace the DECmpp 12000/Sx DPU fan tray:
1.
Open the front and rear doors.
2.
Turn off the DPU. Set the 30 A circuit breaker OFF, and disconnect the power
cord from the power source.
3.
From the back of the DPU, unplug the power cable that runs from the power
tray to the fan tray.
4.
Using a 5/16-inch open-end wrench and a 5/16-inch socket wrench, remove
the +5 V bus bars from the +5 V power supply. Gently pull them forward,
and lay them down so that they are out of the way of the fan tray when it is
pulled out.
5.
Remove the four Phillips Screws fastening the fan tray to the enclosure.
6.
Pull the fan tray out smoothly. Be careful not to pinch the +5 V cables. This
can break the insulation, causing the +5 V power to short to ground.
7.
Note the arrow indicating the tray’s proper orientation. This is important
when installing the new fan tray.
8.
Slide the new fan tray in. Be careful not to pinch the +5 V cables. This can
break the insulation, causing the +5 V power to short to ground.
9.
Replace the four Phillips Screws, securing the fan tray to the frame.
10. Connect the power cable to the fan tray.
11. Connect the +5 V bus bars. Make sure that the bus bars are not shorting to
the frame or to each other.
12. With an ohmmeter, check the resistance b5 V and ground. A zero
ohm reading indicates a short which must be investigated.
13. Turn on the DPU, and verify that the new fan is operating properly.
6–18 Removal and Replacement Procedures
