48 TroubleshootingBuilt-in DiagnosticsYour monitor has a built-in diagnostic tool that helps you determine if thescreen abnormality you are experiencing is an inherent problem with yourmonitor, or with your computer and video card.12345NOTE: You can run the built-in diagnostics only when the video cableis unplugged and the monitor is in self-test mode.To run the built-in diagnostics:1. Ensure that the screen is clean (no dust particles on the surface ofthe screen).2. Unplug the video cable(s) from the back of the computer ormonitor. The monitor then goes into the self-test mode.3. Press and hold the Button 1 and Button 4 on the front panelsimultaneously for 2 seconds. A gray screen appears.4. Carefully inspect the screen for abnormalities.5. Press the Button 4 on the front panel again. The color of the screenchanges to red.6. Inspect the display for any abnormalities.7. Repeat steps 5 and 6 to inspect the display in green, blue, black,white screens.The test is complete when the white screen appears. To exit, press theButton 4 again.If you do not detect any screen abnormalities upon using the built-indiagnostic tool, the monitor is functioning properly. Check the video cardand computer.