Lenovo YOGA 900 User Manual page 31

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.
Battery pack problems
Your computer shuts down
before the battery status
indicator shows empty.
-or-
Your computer operates
after the battery status
indicator shows empty.
•
Do the following:
- If you are using the AC power adapter or the battery pack,
and the battery status indicator is on, press F12 (
make the screen brighter.
- If the power indicator is blinking, press the Power button to
resume from sleep mode.
- Press F9 (
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.
•
Recharge the battery.
27
Chapter 4. Troubleshooting
) to confirm whether the backlight of the
) to