Service manual

Servicing the CPU 2-11

There are at least two factors to consider when adding or replacing a CPU:

1. The desire to retain the system environment.

2. The possibility that the new CPU is at a higher firmware revision

than other CPUs in the system.

shows the mismatch message

should the firmware differ between CPUs. In this case the newer sec-

ondary has a higher firmware revision than the older primary.

The procedure described here takes these into consideration.

After you have removed and replaced the defective CPU following the in-

structions 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 primary CPU.

3. Use the update -e command to copy the EEPROM environment vari-

ables from the primary processor to the new secondary. (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.)

4. Use the set cpu command to connect the console terminal to the new

CPU.

5. If there is a firmware revision mismatch, you will want to update the

FEPROMs on the older CPUs. Since you are already running the con-

sole from the newest CPU, 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.