5.7 Replacing Power Cables to the DA Backplane
5.7 Replacing Power Cables to the DA Backplane
Follow these steps to replace the +5 V, +12 V, or ground cable between the
power supply and the DA backplane bus bar system. Figure 5–6 shows the cable
connections. Put on an ESD wrist strap as a precautionary measure.
1. Turn the PDA circuit breaker OFF.
2. Unplug the PDA from the power source.
3. Unplug all DA controller PCBs and slide them out 1 inch from the backplane.
4. Unplug all disk canisters and slide them out 1 inch from the DA backplane.
5. Label all power cables.
6. Remove the power/fan tray (Section 5.6).
7. Remove those disk canisters blocking access to the DA backplane bus bar.
8. Remove the nut fastening the cable to the appropriate power bridge high-
current connector.
9. Remove the screw and nut connecting the cable to the backplane bus bar.
10. Fasten the replacement cable to the backplane bus bar, using a screw and
nut.
11. With the nut removed above, fasten the replacement cable to the power bridge
high-current connector.
12. Using an ohmmeter, verify that there are no shorts between cables or to
ground.
13. Replace the power/fan tray.
14. Return all disk canisters to their slots and plug in all disk canisters and DA
controller PCBs.
15. Turn the PDA circuit breaker ON.
5–12 Removal and Replacement Procedures
