HP Compaq tc4400 User manual

Troubleshooting
Document Part Number: 383067-003
December 2005

Troubleshooting ii
Contents
1 Quick checklist
The computer will not start up. . . . . . . . . . . . . . . . . . . . . 1–2
The computer screen is blank. . . . . . . . . . . . . . . . . . . . . . 1–3
The software is functioning abnormally. . . . . . . . . . . . . . 1–5
The computer is turned on, but is not responding.. . . . . . 1–6
The computer is unusually warm. . . . . . . . . . . . . . . . . . . 1–7
An external device is not working. . . . . . . . . . . . . . . . . . 1–8
The computer cannot connect to a wireless network. . . . 1–9
2 Customer Care
Preparing to contact Customer Care . . . . . . . . . . . . . . . . 2–1
Contacting Customer Care by e-mail or telephone . . . . . 2–2
Taking the computer to a service partner. . . . . . . . . . . . . 2–2

Troubleshooting 1–1
1
Quick checklist
If you experience computer problems, follow the troubleshooting
steps below.
1. Refer to the information in this chapter.
2. Access additional information about the computer and
Web site links through the Help and Support Center.
✎Although many checkup and repair tools require an Internet
connection, other tools can help you fix a problem when the
computer is offline.
3. Contact Customer Care for any further assistance. Refer
to the “Customer Care” chapter in this guide.

1–2 Troubleshooting
Quick checklist
The computer will not start up.
To turn on the computer, press the power button. When the
computer is turned on, the power light is turned on.
If the computer and the power light are not turned on when you
press the power button, adequate power may not be available to
the computer.
The suggestions below may help you determine why the
computer will not start up.
■If the computer is plugged into an AC outlet, verify that the
AC outlet is providing adequate power by plugging another
electrical device into the outlet.
■If the computer is running on battery power or is plugged into
an external power source other than an AC outlet, plug the
computer into an AC outlet using the AC adapter. Be sure the
power cord and AC adapter connections are secure.
■If the computer is running on battery power:
❏Remove the primary battery pack and travel battery pack
(if applicable) and plug the computer into an AC outlet
using the AC adapter. If the computer starts up, one of the
battery packs may need to be replaced.
❏If the battery light on the front of the computer is
blinking, the battery pack has reached a low-battery
condition, which may not allow the computer to start up.
Plug the computer to an AC outlet using the AC adapter
to start the computer and allow the battery to charge.

Quick checklist
Troubleshooting 1–3
The computer screen is blank.
If you have not turned off the computer but the screen is blank,
one or more of the following may be the cause:
■The computer may be in standby or hibernation.
■The computer may not be set to display the image on the
computer screen.
■The display switch or the ambient light sensor (select
models only) may not be functioning properly.
The suggestions below may help you determine why the
computer screen is blank.
■To resume from standby or restore from hibernation,
briefly press the power button.
Standby and hibernation are energy-saving features that
can turn off the display. Standby and hibernation can be
initiated by the system while the computer is in Microsoft®
Windows® but is not in use, or when the computer has
reached a low-battery condition. To change these and other
power settings, select Start > Control Panel > Performance
and Maintenance > Power Options.
■To transfer the image to the computer screen, press fn+f4.
On most models, when an optional external display device,
such as a monitor, is connected to the computer, the image
can be displayed on the computer screen or the external
display, or on both devices simultaneously. When you press
fn+f4 repeatedly, the image alternates among the computer
display, one or more external display devices, and
simultaneously displays on all devices.

1–4 Troubleshooting
Quick checklist
■Press the display switch on the computer to confirm that the
switch moves freely.
The display switch is normally located on the upper-left
corner of the keyboard.
■If the computer has a magnetic display switch (select models
only), be sure that the computer is not near a strong magnetic
field and that no magnetized items (for example, a
magnetized screw driver) are laying on the computer.
■If the computer has an ambient light sensor (select models
only), be sure that the sensor is not obstructed.
The ambient light sensor is normally located on the lower-left
corner of the display.

Quick checklist
Troubleshooting 1–5
The software is functioning
abnormally.
If the software becomes unresponsive or responds abnormally:
■Restart the computer:
❏In Windows XP Home, select Start > Turn Off
Computer > Restart.
❏In Windows XP Professional, select Start > Turn Off
Computer > Restart > OK. (If you have been registered
to a domain, the button you click will be called Shut
Down instead of Turn Off Computer.)
If you cannot restart the computer using these procedures,
refer to the next section, “The computer is turned on, but is
not responding.”
■Run a virus scan.
■If the computer feels unusually warm, allow it to cool to
room temperature. For more information about computer
overheating, refer to “The computer is unusually warm.”later
in this guide.
■If you are using an optional wireless mouse, make sure that
the mouse battery has an adequate charge.

1–6 Troubleshooting
Quick checklist
The computer is turned on, but is not
responding.
If the computer is turned on, but is not responding to software
applications or keyboard commands, try first to shut down
the computer through the operating system by selecting Start >
Turn Off Computer > Turn Off. (If you have been registered to
a domain, the button you click will be called Shut Down instead
of Turn Off Computer.)
If the computer remains unresponsive, try the emergency
shutdown procedures in the following sequence:
1. If the computer is in Windows, press ctrl+alt+delete.Then,
select Shut Down > Turn Off.
2. If you cannot shut down the computer by using ctrl+alt+delete,
press and hold the power button for at least 5 seconds.
3. If you cannot shut down the computer by using the power
button, unplug the computer from external power and remove
the battery pack.
✎If you cannot turn the computer back on after shutting it down,
refer to “The computer will not start up.”

Quick checklist
Troubleshooting 1–7
The computer is unusually warm.
It is normal for the computer to feel warm to the touch while it
is in use. But if the computer feels unusually warm, it may be
overheating because a vent is blocked.
If you suspect that the computer is overheating, allow the
computer to cool to room temperature. Then be sure to keep all
vents free from obstructions while you are using the computer.
ÄCAUTION: To prevent overheating, do not obstruct vents. Use the computer only on a hard, flat surface. Do not allow another hard
surface, such as a printer, or a soft surface, such as a pillow or a thick
rug or clothing, to block airflow.
✎The computer fan starts up automatically to cool internal
components and prevent overheating. It is normal for the internal
fan to cycle on and off during routine operation.

1–8 Troubleshooting
Quick checklist
An external device is not working.
If an external device does not function as expected:
■Turn on the device as instructed in the device user guide.
Some devices, such as monitors and printers, may not be
powered by the computer, and must be turned on before the
computer is turned on.
■Be sure that
❏All device connections are secure.
❏The device is receiving electrical power.
❏The device is compatible with your operating system. For
compatibility information, refer to the Web site of the
device manufacturer.
❏The correct drivers are installed and updated. Drivers
may be available on a CD included with the device or
on the Web site of the device manufacturer.

Quick checklist
Troubleshooting 1–9
The computer cannot connect to a
wireless network.
■Verify that the wireless devices are enabled.
❏Be sure that the wireless light on the computer is on. If
the light is off, press the wireless button to turn it on.
❏Be sure that the wireless hardware is properly installed
by ensuring there is no red or yellow marking next to the
device name in Device Manager.
1. Select Start > My Computer.
2. Right-click in the window and select Properties >
Hardware tab > Device Manager.
✎If the wireless button is off or the Bluetooth or WWAN
device is disabled in Computer Setup, the Bluetooth or
WWAN device will not appear in Device Manager.
❏Open Wireless Assistant and be sure that the wireless
devices are enabled and on. Select Start > HP Info
Center > HP Wireless Assistant.
❏Be sure that the wireless devices are enabled in Computer
Setup or the Setup utility.
1. Open Computer Setup or the Setup utility by turning
on or restarting the computer, and then pressing f10
while the “F10 = ROM Based Setup” message or the
“Press <F10> to enter setup” message is displayed in
the lower-left corner of the screen.
2. Use the arrow keys to select Advanced > Device
options or Advanced and then press enter.

1–10 Troubleshooting
Quick checklist
■Be sure that the Windows Wireless Network Connection
window can display the network.
❏Click the Refresh button so that Windows will scan all
channels for available access points.
❏Be sure that the computer is within optimal range of the
wireless router (access point).
❏Be sure that the computer wireless antennae are free from
obstructions.
❏If the Wireless Network Connection window displays the
“Windows cannot configure this wireless connection”
message, or the Wireless Networks tab is unaccessible
or missing from the Wireless Network Connection
Properties window, check to see if a third-party utility has
been installed. Most third-party configuration utilities
disable the Windows configuration utility. If a third-party
utility has been installed, configure the wireless network
using the third-party utility, or uninstall the third-party
utility and use the Windows configuration utility to
configure the wireless network.
❏Be sure that the wireless network is broadcasting the
network name (SSID). Most wireless routers (access
points) are set to broadcast SSID by default. If SSID
broadcasting was disabled for added security, reenable
it temporarily to confirm that Windows is detecting the
network. When SSID broadcasting is disabled, the
network will not be detected by Windows and will not be
displayed in the list of available networks.
■Verify that the encryption settings are correct by ensuring that
the computer and the wireless router (access point) are using
the same security settings.

Quick checklist
Troubleshooting 1–11
■Be sure that you are getting a valid IP address.
❏Be sure the computer TCP/IP is configured to Obtain an
IP address automatically:
1. Select Start > Control Panel > Network and
Internet Connections > Network Connections.
2. Right-click on a network connection and select
Properties.
3. Click Internet Protocol (TCP/IP), and then click
Properties.
4. Be sure that Obtain an IP address automatically
is selected.
5. Click OK.
❏Be sure that the wireless router (access point) has DHCP
enabled.
❏Use the ipconfig utility to renew an IP address.
1. Select Start > Run.
2. Type cmd.
3. At the prompt, type ipconfig, and then press enter.
4. To renew an IP address, type ipconfig/release, and then
press enter. Then type ipconfig/renew, and then press
enter.
5. Type exit.
■Be sure that you have the latest firmware for the wireless
router (access point).
■Be sure that the wireless router (access point) activity light is
on. If the activity light is not on, unplug the router power
cable and then plug it back in.

1–12 Troubleshooting
Quick checklist
■Be sure that no other electronics, such as a cordless phone, a
fax machine, or a microwave, are in close proximity to the
wireless router (access point).
■Be sure that no large metal surfaces are near the sides of the
wireless router (access point).
■Be sure that the wireless router (access point) is placed as
high as possible in the room, such as on top of a bookcase.
■Check the wireless router (access point) functionality and
configuration.
❏Temporarily disable any wireless encryption to see if the
computer will connect to the wireless network. If the
computer connects to the wireless network when
encryption is disabled, verify that the computer and the
wireless router (access point) are using the same security
settings (Network Authentication, Data Encryption,
Network Key, and Key Index).
❏Change the wireless channel on the wireless router
(access point). Normally channels 3, 6, and 11 are the
optimal channels because they do not overlap each other.
However, if multiple networks are detected in close
proximity, and more than one is using the same channel,
there may be interference.
For additional information, refer to
http://www.hp.com/go/techcenter/wireless.

Troubleshooting 2–1
2
Customer Care
If you are unable to find the help you need by using the Help and
Support Center, you may need to contact Customer Care.
Preparing to contact Customer Care
To receive the fastest possible resolution of your problem, have
the computer and the following information available when
you call or e-mail:
■Product name located on the display or keyboard.
■Serial number (S/N) listed on the service tag.
❏The service tag label is on the bottom of the computer.
❏To display the service tag information on the computer
screen, click My Computer in the Help and Support
Center.
■Date the computer was purchased.
■Conditions under which the problem occurred.
■Error messages that have been displayed.

2–2 Troubleshooting
Customer Care
■The manufacturer and model of any hardware connected to
the computer.
■Operating system version number and registration number.
To display the operating system version number and
registration number, click My Computer in the Help and
Support Center. (On some models, the registration number
may be identified in the Operating System table as the
Product Id).
Contacting Customer Care by e-mail
or telephone
If the computer is connected to the Internet, you can get help by
e-mail or you can access Customer Care telephone numbers
through the Help and Support Center.
Taking the computer to a service
partner
If Customer Care advises you to take your computer to a service
partner, be sure to provide the service partner with the
information listed in “Preparing to contact Customer Care,”
earlier in this chapter. In addition
■Be sure either to delete all passwords or to disclose all
passwords to the service partner so that they can access the
computer.
■Back up all information on the hard drive.
■Provide authorization to the service partner to perform a
system recovery, if needed.

© Copyright 2005 Hewlett-Packard Development Company, L.P.
Microsoft and Windows are U.S. registered trademarks of Microsoft
Corporation.
The information contained herein is subject to change without notice. The
only warranties for HP products and services are set forth in the express
warranty statements accompanying such products and services. Nothing
herein should be construed as constituting an additional warranty. HP shall
not be liable for technical or editorial errors or omissions contained herein.
Troubleshooting
Third Edition December 2005
First Edition May 2005
Document Part Number: 383067-003