Lenovo B4400 User Manual page 31

Sleep problems
The critical low-battery error
message appears, and the
computer immediately turns
off.
The computer enters
sleep mode
immediately after Power-on
self-test (POST).
Note: If the battery is charged and the temperature is within range, have the computer serviced.
The computer does not
return from sleep mode,
and the computer does not
work.
Sound problems
No sound can be heard
from the speaker even
when the volume is turned
up.
Battery problems
Your computer shuts down
before the battery status
indicator shows empty.
-or-
Your computer operates
after the battery status indi-
cator shows empty.
The computer does not
operate with a fully charged
battery.
• The battery power is getting low. Connect the AC
power adapter to the computer, or replace the battery
with a fully charged one.
• Make sure that:
- The battery is charged.
- The operating temperature is within the acceptable
range. See "Chapter 2. Use and care Information" of
Lenovo Safety and General Information Guide.
• If your computer is in sleep mode, connect the AC
power adapter to the computer and then press any
key or the power button.
• If the system still does not return from sleep mode,
stops responding, or cannot be turned off, reset the
computer. Unsaved data may be lost. To reset the
computer, press and hold the power button for 4
seconds or more. If the computer is still not reset,
remove the AC power adapter and the battery.
• Make sure that:
- The mute function is off.
- The combo audio jack is not used.
- The speaker is selected as the playback device.
• Reset the battery gauge using Lenovo Energy
Management. If the problem persists, replace with a
new battery pack.
• The surge protector in the battery might be active.
Turn off the computer for one minute to reset the
protector; then turn on the computer again.
Chapter 4. Troubleshooting
27