HP Compaq dc7800 USDT Troubleshooting Manual page 31

Table 2-6 Solving Display Problems (continued)
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.
"Out of Range" displays on screen.
Cause
Video resolution and refresh rate are set higher than what the
monitor supports.
Vibrating or rattling noise coming from inside a CRT monitor when powered on.
Cause
Monitor degaussing coil has been activated.
Clicking noise coming from inside a CRT monitor.
Cause
Electronic relays have been activated inside the monitor.
ENWW
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.
Solution
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.
Solution
None. It is normal for the degaussing coil to be activated when
the monitor is powered on.
Solution
None. It is normal for some monitors to make a clicking noise
when turned on and off, when going in and out of standby
mode, and when changing resolutions.
Solving Display Problems 25