User Manual

8. Tighten the screws to secure the base cover assembly.

9. Turn the computer over and reinstall the nano-SIM-card tray if you have removed it.

10. Connect the ac power adapter and all disconnected cables to the computer.

Troubleshooting

If the computer does not start up after you reinstall the base cover assembly, disconnect the ac power

adapter and then reconnect it to the computer.

Base cover assembly (for T590 and P53s only)

Prerequisite

Before you start, read Appendix A “Important safety information” on page 85 and print the following

instructions.

Note: Do not remove the base cover assembly when your computer is connected to ac power. Otherwise,

there might be a risk of short circuits.

Replacement procedure

1. Disable the built-in battery. See “Disable Fast Startup and the built-in battery” on page 51.

2. Turn off the computer and disconnect the computer from ac power and all connected cables. Then,

close the computer display

3. Remove the nano-SIM-card tray if your computer comes with one. See “Connect to a cellular network”

on page 13.

4. Turn the computer over.

T490, T590, P43s, and P53s User Guide