HP Z4 G4 Maintenance And Service Manual page 58

Dim characters.
Cause
The brightness and contrast controls are not set properly.
Blurry video or requested resolution cannot be set.
Cause
If the graphics controller was upgraded, the correct graphics
drivers may not be loaded.
Monitor is not capable of displaying requested resolution.
Graphics card is bad.
The picture is broken up, rolls, jitters, or flashes.
Cause
The monitor connections may be incomplete or the monitor may
be incorrectly adjusted.
CRT monitor needs to be degaussed.
Image is not centered.
Cause
Position may need adjustment.
"No Connection, Check Signal Cable" displays on screen.
Cause
Monitor video cable is disconnected.
50 Chapter 6 Troubleshooting without diagnostics
Solution
Adjust the monitor brightness and contrast controls.
Solution
Download the latest graphics drivers from hp.com.
Change resolution.
Replace the graphics card.
Solution
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.
Degauss the CRT monitor. Refer to the documentation that came
with the monitor for instructions.
Solution
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.
Solution
Connect the video cable between the monitor and computer.
CAUTION: Ensure that the computer power is off while
connecting the video cable.