Lenovo 20N4, Hardware Maintenance Manual

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Attention: The system board is sensitive to, and can be damaged by, electrostatic discharge (ESD). Before
touching it, establish personal grounding by touching a ground point with one hand or by using an ESD strap.
Before servicing the computer
Carefully read this topic before servicing the computer.
Disabling the built-in battery
Before replacing any FRU, ensure that you disable Fast Startup first and then disable the built-in battery.
To disable Fast Startup, do the following:
1. Go to Control Panel, and then change the view of Control Panel from Category to Large icons or Small
icons.
2. Click Power Options , and then click Change 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, do the following:
1. Restart your computer. When the logo screen is displayed, immediately press F1 to enter ThinkPad
Setup.
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.
Removing a major FRU
This section provides instructions on how to remove a major FRU.
1010 Removing the nano-SIM card and the nano-SIM-card tray
Some models you are servicing might have a nano-SIM card installed.
After you finish the servicing, ensure that you install the card and the tray back into the slot firmly.
1020 Base cover assembly
For access, remove this FRU:
• “1010 Removing the nano-SIM card and the nano-SIM-card tray” on page 64
64
T590 and P53s Hardware Maintenance Manual