The frequency range is out of display specifications, or the
incoming resolution is higher than 1280 x 1024. The video
data turns off and this warning message appears.

Check that the scanning frequency is in a horizontal range of 24 to
80 kHz and a vertical range of 55 to 75 Hz. Or check that the display
resolution is set to 1280 x 1024 or lower.

Display indicates “No Video”

There is no video-input signal from the source video port.
The OSD shows this message.

Check that the video cable is connected securely to the computer
and the display.