Digital Equipment EK-SFXXS-SG-003, Service Manual

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4–4 DECarray FRU Removal and Replacement
4.2 Power Controller
The only FRU in the cabinet is the power controller. If it is not
functioning correctly, then part of the cabinet or the entire cabinet will
not power up. This power controller is a single FRU; if it fails, replace it.
To replace a power controller, perform the following steps.
NOTE
Make sure that you have the same power controller variants when
you replace the failed power controller. The 881–A is the 120
variant and the 881–B is the 240 variant.
1. At the system console, dismount all the ISEs.
2. Access the power controller and storage enclosure by opening the
cabinet doors.
3. Take the disk ISEs in all storage enclosures off-line:
a. Press and release all Ready buttons on the OCP of all storage
enclosures in the DECarray. Wait for the Ready LEDs to go out.
b. At the front of each storage enclosure, set the drive dc power
switches to off . The LEDs should go out to indicate that power
has been removed from the disk ISE. If any LED does not go out,
suspect a faulty switch.
CAUTION
Wear an ESD grounding strap at all times while handling the
storage enclosure or any of its FRUs.
4. At the rear of the cabinet, turn off all storage enclosures by pressing
the ac power switch on rear of the enclosure to off.