Replace A Cru; Base Cover Assembly - Lenovo 21C3S0RL00 User Manual

1. Go to Control Panel and view by Large icons or Small icons.
2. Click Power Options, and then click Choose what the power buttons do on the left pane.
3. Click Change settings that are currently unavailable at the top.
4. If prompted by User Account Control (UAC), click Yes.
5. Clear the Turn on fast startup check box, and then click Save changes.
To disable the built-in battery:
1. Restart your computer. When the logo screen is displayed, immediately press F1 to enter the UEFI BIOS
menu.
2. Select Config ➙ Power. The Power submenu is displayed.
3. Select Disable Built-in Battery and press Enter.
4. Select Yes in the Setup Confirmation window. The built-in battery is disabled and the computer turns off
automatically. Wait three to five minutes to let the computer cool.

Replace a CRU

Follow the replacement procedure to replace a CRU.

Base cover assembly

Prerequisite
Before you start, read Generic Safety and Compliance Notices
Notes: Do not remove the base cover assembly in the following situations. Otherwise, there might be a risk
of short circuits.
• When your computer has the removable battery installed
• When your computer is connected to ac power
For access, do the following:
1. Disable the built-in battery. See "Disable Fast Startup and the built-in battery" on page 43.
2. Turn off the computer and disconnect the computer from ac power and all connected cables.
3. Remove the nano-SIM-card tray if your computer comes with one. See "Connect to a cellular network
(for selected models)" on page 12
4. Close the computer display and turn over the computer.
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ThinkPad L14 Gen 3 and ThinkPad L15 Gen 3 User Guide
and print the following instructions.