Lenovo B470E Sleep or hibernation problems, Computer screen problems, Sound problems, Problem

Sleep or hibernation problems

Problem	Solution
The critical low-battery error message appears, and the	The battery power is getting low. Connect the ac power
computer immediately turns off.	adapter to the computer, or replace the battery with a
	fully charged one.
The computer enters sleep mode immediately after	Make sure that:
Power-on self-test (POST).	• The battery is charged.
	• The operating temperature is within the acceptable
	range. See “Use and care information” in the Safety
	and Warranty Guide that comes with your computer.

Computer screen problems

Problem	Solution
The screen is blank.	• Do the following:
	– If you are using the ac power adapter, or using the
	battery, and the battery status indicator is on, press
	Fn+up arrow to make the screen brighter.
	– If the power indicator is in blinking, press the power
	button to resume from the sleep mode.
	– If the problem persist, follow the solution in the
	following problem “The screen is unreadable or
	distorted.”
	– Press Fn+F2 to confirm whether the LCD screen has
	been turned off.
The screen is unreadable or distorted.	Make sure that:
	• The display device driver is installed correctly.
	• The screen resolution and color quality are correctly
	set.
	• The monitor type is correct.
Incorrect characters appear on the screen.	Did you install the operating system or application
	program correctly? If they are installed and configured
	correctly, have the computer serviced.

Sound problems

Problem	Solution
No sound can be heard from the speaker even when the	Make sure that:
volume is turned up.	• The mute function is off.
	• The headphone jack is not used.
	• Speakers are selected as the playback device.

Chapter 5. Troubleshooting 25