HP DC7800 - Manual (Page 244)

Blurry video or requested resolution cannot be set.
Cause Solution
If the graphics controller was upgraded, the correct graphics
drivers may not be loaded. Install the video drivers included in the upgrade kit.
Monitor is not capable of displaying requested resolution. Change requested resolution.
Graphics card is bad. Replace the graphics card.
The picture is broken up, rolls, jitters, or flashes.
Cause Solution
The monitor connections may be incomplete or the monitor
may be incorrectly adjusted. 1. Be sure the monitor cable is securely connected to the
computer.
2. In a two-monitor system or if another monitor is in close
proximity, be sure the monitors are not interfering with
each other’s electromagnetic field by moving them apart.
3. Fluorescent lights or fans may be too close to the monitor.
Monitor needs to be degaussed. Degauss the monitor. Refer to the documentation that came
with the monitor for instructions.
Image is not centered.
Cause Solution
Position may need adjustment. Press the monitor's Menu button to access the OSD menu.
Select ImageControl/ Horizontal Position or Vertical
Position to adjust the horizontal or vertical position of the
image.
“No Connection, Check Signal Cable” displays on screen.
Cause Solution
Monitor video cable is disconnected. Connect the video cable between the monitor and computer.
CAUTION: Ensure that the computer power is off while
connecting the video cable.
“Out of Range” displays on screen.
Cause Solution
Video resolution and refresh rate are set higher than what the
monitor supports. Restart the computer and enter Safe Mode. Change the
settings to a supported setting then restart the computer so that
the new settings take effect.
Table D-6 Solving Display Problems (continued)
232 Appendix D Troubleshooting Without Diagnostics