User Manual

• Problem: My computer does not run on battery power.
Solution: Check the following items:
1. Remove and reinstall the removable battery to ensure that it is properly connected.
2. If the battery runs out of power, attach the ac power adapter to recharge the battery.
3. If the battery is charged but the computer does not run, replace the battery with a new one.
• Problem: The system does not respond, and I cannot turn off the computer.
Solution: Turn off the computer by pressing and holding the power button for four seconds or more. If the
computer still does not respond, remove the ac power adapter and the battery.
Power button problem
Problem: The system does not respond, and I cannot turn off the computer.
Solution: Turn off the computer by pressing and holding the power button for four seconds or more. If the
system still does not respond, remove the ac power adapter and reset the system by inserting one end of a
needle or a straightened paper clip into the emergency-reset hole. To locate the emergency-reset hole, see
“Bottom view” on page 5.
Boot problems
Print these instructions now and keep them with your computer for reference later.
• Problem: I receive an error message before the operating system loads.
Solution: Follow the appropriate corrective actions for power-on self-test (POST) error messages.
• Problem: I receive an error message while the operating system is loading the desktop configuration after
the POST is completed.
Solution: Find solutions by searching for the error message at the following Web sites:
–
http://www.lenovo.com/support
– https://support.microsoft.com/
Sleep and hibernation problems
• Problem: The computer enters sleep mode unexpectedly.
Solution: If the microprocessor overheats, the computer automatically enters sleep mode to allow the
computer to cool and to protect the microprocessor and other internal components. Check the settings
for sleep mode.
• Problem: The computer enters sleep mode immediately after the power-on self-test.
Solution: Ensure that:
– The battery is charged.
– The operating temperature is within the acceptable range. See “Operating environment” on page 11.
If the problem persists, have the computer serviced.
• Problem: A critical low-battery error occurs, and the computer immediately turns off.
Solution: The battery power is getting low. Plug the ac power adapter into an electrical outlet and then
into the computer. Alternatively, replace the battery with a charged one.
• Problem: The computer display remains blank after you press Fn to resume from sleep mode.
Solution: Check whether an external monitor was disconnected or turned off while the computer was in
sleep mode. If you disconnected or turned off the external monitor, connect it or turn it on before resuming
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A475 User Guide