IBM A21P, A21M, A22P, A22M Retaining serial numbers, Restoring the serial number of the system unit

FRU replacement notices

vMake sure you use the correct screw. If you have a torque screwdriver, tighten all screws firmly to the torque shown in the table. Never use a screw that you removed. Use a new one. Make sure the screws are tightened firmly.

Retaining serial numbers

This section includes the following descriptions:

v“Restoring the serial number of the system unit”

v“Retaining the UUID”

Restoring the serial number of the system unit

When the computer was manufactured, the EEPROM on the system board was loaded with the serial numbers of the system and all major components. These numbers need to remain the same throughout the life of the computer.

If you replace the system board, you must restore the serial number of the system unit to its original value.

Before replacing the system board, save the original serial number by doing the following:

1.Install the ThinkPad hardware maintenance diskette version 1.62, and restart the computer.

2.From the main menu, select 1. Set System Identification.

3.Select 2. Read S/N data from EEPROM.

The serial number for each device is displayed. Write down the serial number of the system unit, designated as follows:

20: System unit serial number

After you have replaced the system board, restore the serial number by doing the following:

1.Install the ThinkPad hardware maintenance diskette version 1.62 and restart the computer.

2.From the main menu, select 1. Set System Identification.

3.Select 1. Add S/N data from EEPROM. Follow the instructions on the screen.

Note: The serial number of the system unit is written on the label attached on the bottom of the computer.

Retaining the UUID

The Universally Unique Identifier (UUID) is a 128-bit number uniquely assigned to your computer at production and stored in the EEPROM of your system board. The algorithm that generates the number is designed to provide

ThinkPad A20m/p, A21m/p and A22m/p 57