Lenovo X300 manual Retaining serial numbers, Restoring the serial number of the system unit

Retaining serial numbers

This section includes the following descriptions:

v“Restoring the serial number of the system unit”

v“Retaining the UUID”

v“Reading or writing the ECA information” on page 57

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 1.73 or later, 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 of each device in your computer is displayed; the serial number of the system unit is listed as follows:

v20: Serial number Write down that number.

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

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

1.Install the ThinkPad Hardware Maintenance Diskette Version 1.73 or later 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.

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 unique IDs until the year A.D. 3400. No two computers in the world have the same number.

When you replace the system board, you must set the UUID on the new system board as follows:

1.Install the ThinkPad Hardware Maintenance Diskette Version 1.73 or later, and restart the computer.

2.From the main menu, select 4. Assign UUID.

A new UUID is created and written. If a valid UUID already exists, it is not overwritten.

56ThinkPad X300 Hardware Maintenance Manual