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
electrostatic discharge strap.
Before servicing the computer
Carefully read this topic before servicing the computer.
Removing external devices
Before you start servicing, ensure that you remove all external devices installed by the customer, such as
microSD card, dock, and external display.
Disabling the built-in battery
Before replacing any FRU/CRU, ensure that you 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 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, 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.
Remove the microSD card
Removal steps of the microSD card
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E490s and S3 Hardware Maintenance Manual