58 | Troubleshootingor4 This box also appears during normal system operation, if the video cable becomesdisconnected or damaged.5 Turn Off your monitor and reconnect the video cable; then turn On both yourcomputer and the monitor.If your monitor screen remains blank after you use the previous procedure, check yourvideo controller and computer, because your monitor is functioning properly.Built-in DiagnosticsYour monitor has a built-in diagnostic tool that helps you determine if the screenabnormality you are experiencing is an inherent problem with your monitor, or with yourcomputer and video card.NOTE: You can run the built-in diagnostics only when the video cable is unpluggedand the monitor is in self-test mode.
