HP proone 400 g2 Maintenance & Service Manual page 108

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.
98 Chapter 7 Troubleshooting without diagnostics
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.
To enter Safe Mode in Windows 7:
1. Restart the computer.
2. Press and hold the F8 key as your computer restarts, before
the Windows logo appears. If the Windows logo appears,
you must restart the computer and try again.
3. On the Advanced Boot Options screen, use the arrow keys to
highlight the safe mode option you want, and then press
Enter.
4. Log on to your computer with a user account that has
administrator rights.
When your computer is in safe mode, Safe Mode displays in
the corners of your monitor. To exit safe mode, restart your
computer and let Windows start normally.
To enter Safe Mode in Windows 8.1: