Built-In Diagnostics - Dell S2421H Simplified Service Manual

Built-in diagnostics

Your monitor has a built-in diagnostic tool that helps you determine if the screen
abnormality you are experiencing is an inherent problem with your monitor, or with your
computer and video card.
To run the built-in diagnostics:
1. Ensure that the screen is clean (no dust particles on the surface of the
screen).
2. Press and hold Button 4 for four seconds, a menu appears on the screen.
3. Select the built-in diagnostics
4. Carefully inspect the screen for abnormalities.
5. Press Button 1 on the front panel again. The color of the screen changes to
red.
6. Inspect the display for any abnormalities.
7. Repeat steps 5 to 6 to inspect the display when it changes to green, blue,
black, white, and text screens.
The test is complete when the text screen appears. To exit, press Button 1 again.
If you do not detect any screen abnormalities during the built-in diagnostic tool, the
monitor is functioning properly. Check the video card and computer.
5. Trouble Shooting Instructions
1 2 3 4
option. A gray screen appears.
5