6.4 Replacing DPU Power Trays
6.4.4 Installing the DECmpp 12000–LC/Sx Power Tray
Take the following steps to install the power tray:
1.
Slide the new power tray into place.
2.
Lift the power supply cables out of the way and slide in the power tray.
3.
Replace the four Phillips Screws, fastening the power tray to the frame.
4.
Replace the –5 V, +12 V, and –12 V wires:
•
Powertec power supply — Use a 5/16-inch socket wrench to secure the
nuts after the wires are in place; to avoid snapping the power post,
apply minimum force when tightening the nuts. Refer to Table 6–2 and
Figure 6–8 when connecting the wires.
•
HC Power supply — Use a Phillips screwdriver to secure the wires to the
power supply, referring to Table 6–3 and Figure 6–9.
5.
Connect the +5 V cables.
6.
Connect the cables on the back of the power tray.
7.
Before turning on the system power, make sure that all the cables have been
installed properly and ensure that there are no shorts in the DC voltage
supply system. With an ohmmeter, check the +5 V, –5 V, +12 V, and –12 V
connections with respect to ground. A zero ohm reading indicates a short and
must be investigated before applying power.
8.
Turn on the power to the DPU.
9.
Measure the voltage levels, and, if needed, fine tune the levels on the power
supplies. Measure the voltages at the backplane. Voltage settings are
described in Chapter 3.
10. Turn the DPU power off.
11. Using the ejector levers, replace the card cage PCBs, seating them firmly into
the backplane.
12. Turn the DPU power on.
13. On the backplane, measure the power supply voltages again, and adjust if
necessary.
14. Close the DPU doors.
15. Run diagnostics and application programs to verify proper performance.
Removal and Replacement Procedures 6–15
