Lenovo B450 User Manual page 51

The computer does not
return from sleep mode and
does not work.
Note: 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. However,
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 adapter and
the battery.
• If the computer does not return from sleep mode, it
may have entered hibernation mode automatically
because the battery is depleted. Check the power
indicator.
• If your computer is in sleep mode connect the AC
adapter to the computer, then press any key or the
power button.
• If your computer is in hibernation mode or power-off
state. Connect the AC adapter to the computer, then
press the power button to resume operation.
Chapter 5. Troubleshooting
37