Dell OptiPlex 755 - Manual (Page 207)

Video and Monitor Problems
The screen is blank
The screen is difficult to read
Check the monitor cable connection —
l Ensure that the monitor cable is connected to the correct graphics card (for dual graphics card configurations).
l If you are using the optional DVI-to-VGA adapter, ensure that the adapter is correctly attached to the graphics card and monitor.
l Ensure that the monitor cable is connected as shown on the setup diagram for your computer.
l Remove any video extension cables and connect the monitor directly to the computer.
l Swap the computer and monitor power cables to determine if the monitor's power cable is defective.
l Check the connectors for bent or broken pins (it is normal for monitor cable connectors to have missing pins).
Check the monitor power light —
l If the power light is lit or blinking, the monitor has power.
l If the power light is off, firmly press the button to ensure that the monitor is turned on.
l If the power light is blinking, press a key on the keyboard or move the mouse to resume normal operation.
Test the electrical outlet — Ensure that the electrical outlet is working by testing it with another device, such as a lamp.
Check the diagnostic lights —
See Diagnostic Lights .
Check the monitor settings — See the monitor documentation for instructions on adjusting the contrast and brightness, demagnetizing (degaussing) the
monitor, and running the monitor self-test.
Move the subwoofer away from the monitor — If your speaker system includes a subwoofer, ensure that the subwoofer is positioned at least 60 centimeters
(2 feet) away from the monitor.
Move the monitor away from external power sources — Fans, fluorescent lights, halogen lamps, and other electrical devices can cause the screen image to
appear shaky. Turn off nearby devices to check for interference.
Rotate the monitor to eliminate sunlight glare and possible interference
Adjust the Windows display settings —
Windows XP:
1. Click Start® Control Panel® Appearance and Themes.
2. Click the area you want to change or click the Display icon.
3. Try different settings for Color quality and Screen resolution.
Windows Vista:
1. Click Start ® Control Panel® Hardware and Sound® Personalization® Display Settings.
2. Adjust Resolution and Colors settings, as needed.
3D image quality is poor
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
NOTICE: If your computer came with a PCI graphics card installed, removal of the card is not necessary when installing additional graphics cards;
however, the card is required for troubleshooting purposes. If you remove the card, store it in a safe and secure location. For information about your
graphics card, go to support.dell.com.
NOTE: For troubleshooting procedures, see the monitor's documentation.