HP ProDesk 405 G4 Small Form Factor Maintenance And Service Manual page 92

Dim characters.
Cause
The brightness and contrast controls are not set properly.
Cables are not properly connected.
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.
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.
82 Chapter 6 Troubleshooting without diagnostics
Solution
Adjust the monitor brightness and contrast controls.
Check that the graphics cable is securely connected to the graphics
card (if applicable) or video connector and the monitor.
Solution
Install the video drivers included in the upgrade kit.
Change requested 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 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.