Sound And Speaker Problems; If The Display Is Difficult To Read; If Only Part Of The Display Is Readable; If You Have A Problem With Integrated Speakers - Dell Latitude C840 User Manual

Check the AC adapter — Check the AC adapter cable connections. If the AC adapter has a light, ensure that it is on.
Connect the computer directly to an electrical outlet —
that the computer turns on.
Adjust the Power Properties —
Switch the video image — If your computer is attached to an external monitor, press

If the display is difficult to read

Adjust the brightness — See "Adjusting
Move the subwoofer away from the computer or monitor —
subwoofer is at least 60 cm (2 ft) away from the computer or external monitor.
Eliminate possible interference —
Rotate the computer to face a different direction —
Adjust the Windows display settings
Windows XP
1. Click the Start button and then click Control Panel.
2. Click Appearance and Themes.
3. Click the area you want to change or click the Display icon.
4. Try different settings for Color quality and Screen resolution.
Windows 2000
1. Click the Start button, point to Settings, and then click Control Panel.
2. Double-click the Display icon and then click the Settings tab.
3. Try different settings for Colors, Screen area, and Advanced Settings.
Run the Video diagnostics tests —
run the Video device group in the
See "Error Messages" — If an error message appears, see

If only part of the display is readable

Connect an external monitor
1. Turn off your computer and connect an external monitor to the computer.
2. Turn on the computer and the monitor and adjust the monitor brightness and contrast controls.
If the external monitor works, the computer display or video controller may be defective.

Sound and Speaker Problems

Fill out the Diagnostics Checklist as you complete these checks.

If you have a problem with integrated speakers

Bypass power protection devices, power strips, and the extension cable to verify
Search for the keyword standby in Windows Help or Windows Help and Support Center.
Brightness" for instructions on adjusting the brightness.
If your external speaker system includes a subwoofer, ensure that the
Turn off nearby fans, fluorescent lights, halogen lamps, or other appliances.
Eliminate sunlight glare, which can cause poor picture quality.
If no error message appears and you still have a display problem, but the display is not completely blank,
Dell Diagnostics.
"Error
to switch the video image to the display.
Messages."
Contact Dell.