Digital Equipment DEC 10000, Service Manual

Page: 35 / 70

Servicing the CPU 2-9
There are at least two factors to consider when replacing a primary CPU:
1. The desire to retain the system environment.
2. The possibility that the new CPU is at a higher or lower firmware re-
vision than other CPUs in the system.
2
shows the mismatch mes-
sage should the firmware differ between CPUs. Note that in this case
the newer primary has a higher firmware revision than the secondary.
The procedure described here takes these into consideration.
After you have removed and replaced the defective primary CPU following
the instructions in Chapter 1, take the following steps:
1. Power up the system. If self-test fails, refer to the appropriate
Ad-
vanced Troubleshooting manual; otherwise continue.
2. Note the firmware revision of the new CPU.
3. Use the
set cpu
command to connect the console terminal to another
CPU in the system.
4. Use the
update -e
command to copy the EEPROM environment vari-
ables from the secondary processor to the new primary processor.
(The
update -e
command copies the system serial number and other
parameters that can be set, as well as any additional information
stored in the EEPROM to the target CPU.)
5. If there is a firmware revision mismatch, you should update the FEP-
ROMs on the older CPUs. To do this, run the console on the newer
CPU. Use the
set cpu
command to get to the newer version and then
use the
update -f
command. Note that if there are several CPUs that
need updating, you can use a wildcard to target them all, as in
update
-f kn7aa*.
6. Use the
set eeprom field
command to enter the 8-digit LARS number
and a short message (up to 68 characters), stating the date and reason
for service, into the EEPROM.
7. Boot the system and return control to the customer.
NOTE: If the customer used the
set cpu_primary
command to change the
default which allows all CPUs in the system to become the pri-
mary, the
set cpu
command may not work.
To allow all CPUs in the system to become the primary processor, use the
set cpu_primary ff
command. Modify the
cpu_primary
environment
variable to the customer setting after performing the updates.