HP Vectra VL800 Troubleshooting Manual page 17

NOTE
Symptom....
PC boots correctly, but when
the operating system starts
loading, the screen goes blank or
image is corrupt.
If the screen is still blank or corrupt
Case 5 — Screen Goes Blank or Corrupt Image
When the power button is pressed, the PC starts to boot and there is
initially some activity on the monitor, but then the screen goes blank or
the image is corrupt.
Screen becomes blank.
•
or
Image is corrupt.
•
Before removing the cover, always switch off the display and PC.
Disconnect the power cord and any accessory cables. When checks
have been completed, close the PC and reconnect the power cord and
accessory cables. Verify that the PC boots correctly.
Check that...
The monitor supports the resolution and
selected refresh rate. This type of problem
can occur if the PC is configured using one
monitor, then swapped with another one.
Check that...
The video card is correctly inserted in the
socket on the system board.
Hard disk drive is correctly configured and
cables are connected.
Hard disk drive is accessible.
1 Your PC Does Not Start Correctly
Case 5 — Screen Goes Blank or Corrupt Image
How...
1 Reboot the PC in VGA mode. Then, access Display
Properties through Start, Settings, Control Panel.
2 Change the display resolution and refresh values to settings
that can be handled by your monitor.
How...
1 Follow the instructions indicated in the above Note about
removing the cover and switching off the PC.
2 Remove the AGP card, then carefully re-insert it into the
socket.
3 Replace the cover and reconnect the power cord and
accessory cables. Verify that the PC boots correctly.
Refer to page 24 for further help, if required.
Refer to page 41 for instructions about troubleshooting using HP
e-DiagTools.
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