Lenovo 80SF0001US User Manual page 29

The computer does not
return from sleep mode and
the computer does not
work.
Display panel problems
The screen is blank.
The screen is unreadable or
distorted.
Incorrect characters appear
on the screen.
Sound problems
No sound can be heard
from the speakers even
when the volume is turned
up.
• If your computer is in sleep mode, connect the AC
power adapter to the computer, then press the
Windows button or the Power button.
• If the system still does not return from sleep mode,
your system has stopped responding, and you cannot
turn off the computer; reset the computer. Unsaved
data may be lost. To reset the computer, press and
hold the Power button for eight seconds or more. If
the computer still does not reset, remove the AC
power adapter.
• Do the following:
‐ If you are using the AC power adapter or the
battery, and the battery status indicator is on, press
F12 ( ) to make the screen brighter.
‐ If the power indicator is blinking, press the Power
button to resume from sleep mode.
‐ Press F9 ( ) to confirm whether the backlight of
the LCD screen has been turned off.
‐ If the problem persists, follow the solution in the
next problem "The screen is unreadable or
distorted."
• Make sure that:
‐ The screen resolution and color quality are correctly
set.
‐ The monitor type is correct.
• Is the operating system or programs installed
correctly? If they are installed and configured
correctly, have the computer serviced.
• Make sure that:
‐ The Mute function is off.
‐ The combo audio jack is not being used.
‐ Speakers are selected as the playback device.
Chapter 4. Troubleshooting
25