The monitor does not automatically select the input source. You must use the select input button just to the left of the power button. Repeatedly push the button until the correct input source is selected. Unfortunately when the monitor does not detect the selected input it powers down and the select input button may not work correctly. A way around this is to connect the monitor to a VGA input since that it what it is apparently looking for. Power up the monitor and the input source. Then you can use the select input button to change the selection to the appropriate source, HDMI, DVI, etc. Reconnect the monitor to the new input source.