IBM pSeries 670, Service Manual

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I/O Subsystem Distributed Converter Assembly (DCA)
Notes:
1. If multiple I/O planars or I/O Drawer DCAs are being replaced during a maintenance window, then they
must be replaced one at a time in order to ensure the I/O Drawer serial number does not become
damaged. After a single part is replaced, the I/O drawer needs to have power applied to it and the
system brought to the OK prompt. At this point, the system can be powered off to replace the next
part. An algorithm is used (shortly after the UEPO is turned on) to overwrite the new part. If more than
one part is replaced at a time, the VPD will not be updated and the system will not be able to boot in
LPAR mode.
2. Each I/O subsystem can have up to two DCAs. You can replace each DCA separately. The removal
and replacement procedures are identical for each DCA.
3. This procedure applies to the I/O subsystem DCAs.
4. If a subsystem has two DCAs, each is hot-pluggable. If only one needs to be removed, you do not
have to power off the system. Do not attempt to replace two DCAs at once or to move DCAs from one
I/O drawer to another to troubleshoot a problem. The machine type/serial number will be damaged
when these actions are attempted.
Removal
DANGER
Do not attempt to open the covers of the power supply. Power supplies are not serviceable and
are to be replaced as a unit.
D02
1. Open the rack front door
2. Remove the I/O subsystem front cover.
3. Locate the DCA to be replaced.
4. Note the state of the DCA’s LEDs.
5. Press the green Start Service button on the UEPO switch.
6. Proceed only if all the DCA’s LEDs go off or the repair has been scheduled (System outage - EPO
off),
7. Verify the cable labeling and locations, and then unplug the cables from the DCA.
8. Loosen the left and right captive thumbscrews, using the torque tool (P/N 6422789), alternating
between the fasteners until the unit can slide out of the slot.
Chapter 9. Removal and Replacement Procedures
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