Notes:
•Ensure that you use the correct screw. It is recommended to use new screws for replacements.
•If you have a torque screwdriver, tighten all screws firmly to the torque specified in the screw information table for each step.
•Ensure that the torque screw drivers are calibrated correctly following the country specifications.
Retaining serial numbers
This section includes the following descriptions:
•“Restoring the serial number of the system unit” on page 54
•“Retaining the UUID” on page 55
•“Reading or writing the ECA information” on page 55
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 LENOVO ThinkPad Hardware Maintenance Diskette Version 1.76 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 the system unit is listed as 20: Serial number.
4.Write down that number.
Note: The serial number of the system unit also is 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 LENOVO ThinkPad Hardware Maintenance Diskette Version 1.76 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.
If the MTM and Product ID numbers differ from each other on the rear label, use what is shown for the Product ID field. See example below:
