Lenovo B5400 Notebook - Manual (Page 33)

Chapter 4. Troubleshooting
27
Other problems
Your computer does not
respond. • To turn off your computer, press and hold the power
button for 4 seconds or more. If the computer still
does not respond, remove the battery pack and the
AC power adapter.
• Your computer might lock when it enters sleep mode
during a communication operation. Disable the sleep
timer when you are working on the network.
I need to start the computer
from a connected device,
but the device does not
appear on the boot device
list. • Check the boot mode setting in the BIOS setup utility.
If Boot Mode is set to UEFI, make sure that the device
or the medium in the device supports UEFI boot. If
the device or the medium in the device does not
support UEFI boot, set Boot Mode to Legacy Support.
If the device still does not appear in the boot device
list, replace with a new device or medium.
The connected external
device does not work. • Do not connect or disconnect any external device
cables other than USB while the computer power is
on; otherwise, you might damage your computer.
• When using a high power consumption external
device such as an external USB optical disk drive, use
an external device power adapter. Otherwise, the
device might not be recognized, or system shut down
might result.