Lenovo 20L5, Руководство по техническому обслуживанию аппаратной части, Страница: 66 / 114

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 torque screwdrivers are calibrated correctly following country specifications.
Retaining serial numbers
This topic provides instructions on the following:
• “Restoring the serial number of the system unit” on page 60
• “Retaining the UUID” on page 61
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.
The serial number of the system unit is written on the label attached to the bottom of the computer.
If you cannot find the serial number of the system unit on the bottom of the computer, try the following
method to get the number:
Note: Before you perform the operation, ensure that the UEFI/Legacy setting within the Startup menu in the
ThinkPad Setup program is set to UEFI Only .
1. Connect a USB memory key to the computer.
2. Go to
https://www.lenovo.com/maintenanceutilities
and follow the instructions on the screen to create a
Maintenance Key.
Note: Only an authorized Lenovo service technician can access the above Web site.
3. Restart the computer.
4. When the logo is displayed, press Esc. The ThinkPad Config Information Update Utility interface is
displayed.
5. Type 1 under Enter the action desired , then press Enter. The ThinkPad Serial Number Update Utility for
Asset ID screen is displayed.
6. Type 2 under Enter the action desired , then press Enter. The serial number of each device in your
computer is displayed; the serial number of the system unit is listed as follow:
20- Serial number
7. Record the serial number of the system unit.
After you replace the system board, do the following to restore the serial number of the system unit:
1. Connect the Maintenance Key to the computer.
60
T480 Hardware Maintenance Manual