Lenovo B4400 Laptop User Guide

							Chapter 4. Troubleshooting
27
 Sleep problems
The critical low-battery error 
message appears, and the 
computer immediately turns 
off.The battery power is getting low. Connect the AC 
power adapter to the computer, or replace the battery 
with a fully charged one.
The computer enters 
sleep mode 
immediately after Power-on 
self-test (POST). 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.
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. 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.
Sound problems
No sound can be heard 
from the speaker even 
when the volume is turned 
up.Make sure that:
- The mute function is off.
- The combo audio jack is not used.
- The speaker is selected as the playback device. 
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.Reset the battery gauge using Lenovo Energy 
Management. If the problem persists, replace with a 
new battery pack.
The computer does not 
operate with a fully charged 
battery.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. 
						

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Chapter 4. Troubleshooting
A hard disk drive problem
The hard disk drive does 
not work.In the Startup menu in the BIOS setup utility, make 
sure that the hard disk drive is included in the Boot 
Priority Order list.
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.
The computer does not 
start from a device you 
want.See the Boot Priority Order list of the BIOS setup 
utility. Make sure that the BIOS setup utility is set so 
that the computer starts from the device you want.
Also make sure that the device from which the 
computer starts is enabled. Make sure that the device 
is included in the Boot Priority Order list in the BIOS 
setup utility correctly.
Press F12 when the Lenovo logo appears on the 
screen while the computer is starting up to select the 
device you want the computer starts from.
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 may not be recognized, or system shut down 
may result. 
						

							29
Appendix. CRU (Customer Replaceable Units) 
instructions
Replacing the battery  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
To replace the battery, do the following:
1Turn off the computer. Disconnect the AC power adapter and all cables 
from the computer.
2Close the computer display, and turn the computer over.
3Unlock the manual battery latch  . Hold the spring-loaded battery latch 
in the unlocked position  , remove the battery pack in the direction 
shown by the arrow  . 
Notes:
Make sure the battery has been removed before replacing any devices.
Write down the WLAN serial number on the attached label before removing the backup 
battery and Mini PCI Express Card. The serial number is required by Lenovo to replace 
with the proper unit.
Note:Use only the battery provided by Lenovo. Any other battery could ignite or explode.
a
b
c
1a
b
c 
						

							30
Appendix. CRU (Customer Replaceable Units) instructions
4Install a fully charged battery.
5Slide the manual battery latch to the locked position.
6Turn the computer over again. 
7Connect the AC power adapter and the cables to the computer. 
						

							Appendix. CRU (Customer Replaceable Units) instructions
31
Replacing the backup battery  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
To replace the backup battery, do the following:
1Turn off the computer, then disconnect the AC power adapter and all 
cables from the computer.
2Close the computer display, and then turn the computer over.
3Remove the battery pack.
4Remove the Hard disk drive/Memory/Mini PCI Express Card slot 
compartment cover.
a. Loosen the screws that secure the compartment cover  .
b. Remove the compartment cover  . 
a
b
b
a 
						

							32
Appendix. CRU (Customer Replaceable Units) instructions
5Disconnect the backup battery cable connector  , then pull the backup 
battery upward to remove  .
6Install a new backup battery.
7Reinstall the compartment cover and tighten the screws.
8Reinstall the battery pack.
9Turn the computer over again.
0Connect the AC power adapter and the cables to the computer.
a
b
b
a 
						

							Appendix. CRU (Customer Replaceable Units) instructions
33
Replacing the hard disk drive  - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
You can increase the storage capacity of your computer by replacing the hard 
disk drive with one of greater capacity. You can purchase a new hard disk 
drive from your reseller or Lenovo marketing representative.
The hard disk drive is very sensitive. Incorrect handling may cause damage 
and permanent loss of data on it. Before removing the hard disk drive, make 
a backup copy of all the information on it, and then turn the computer off. 
Never remove the drive while the system is operating, in sleep mode. 
Notes:
Replace the hard disk drive only if you upgrade it or have it repaired. The connectors and 
bay of the hard disk drive were not designed for frequent changes, or drive swapping.
The preinstalled software is not included on an optional hard disk drive.
Handling a hard disk drive
Do not drop the drive or subject it to physical shocks. Put the drive on a material, 
such as soft cloth, that absorbs the physical shock.
Do not apply pressure to the cover of the drive. 
Do not touch the connector. 
						

							34
Appendix. CRU (Customer Replaceable Units) instructions
To replace the hard disk drive, do the following:
1Turn off the computer, then disconnect the AC power adapter and all 
cables from the computer.
2Close the computer display, and then turn the computer over.
3Remove the battery pack.
4Remove the Hard disk drive/Memory/Mini PCI Express Card slot 
compartment cover.
a. Loosen the screws that secure the compartment cover  .
b. Remove the compartment cover  .
a
b
b
a 
						

							Appendix. CRU (Customer Replaceable Units) instructions
35
5Remove the frame fixing screws  .
6Pull the tab in the direction shown by arrow  .
c
c
d
d 
						

							36
Appendix. CRU (Customer Replaceable Units) instructions
7Take out the hard disk drive secured in a metal frame  .
8Remove the screws and detach the metal frame from the hard disk drive.
9Attach the metal frame to a new hard disk drive and tighten the screws.
0Put the hard disk drive gently into the hard disk drive bay with the tab
facing upwards and the connectors facing each other, then push it firmly
into space.
AReinstall the frame fixing screw.
BReinstall the compartment cover and tighten the screws.
CReinstall the battery pack.
DTurn the computer over again.
EConnect the AC power adapter and the cables to the computer.
e
e