Lenovo B450 Notebook - Manual (Page 50)

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Chapter 5. Troubleshooting
Keyboard problems
A number appears when
you enter a letter. • The numeric lock function is on. To disable it, press
Fn + Insert
.
Sleep or hibernation problems
The computer enters sleep
mode unexpectedly. • If the processor overheats, the computer automatically
enters sleep mode to allow the computer to cool and to
protect the processor and other internal components.
Check the settings for sleep mode.
The computer enters sleep
mode immediately after
Power-on self-test (POST). • Make sure that:
- The battery is charged.
- The operating temperature is within the acceptable
range. See “Appendix B. Use and care
information” on page 59.
Note: If the battery is charged and the temperature is within range, have the computer
serviced.
The critical low-battery error
message appears, and the
computer immediately turns
off. • The battery power is getting low. Connect the AC
adapter to the computer, or replace the battery with
a fully charged one.