S231HL Monitor Sometimes Goes Blank Then Flashes VGA Then DVI Then Returns To Normal

Totl

Acer monitor model S231HL will every once in awhile go blank, then in upper right corner with show VGA, then will show DVI, then will return to normal.  What could be causing that?  Have tried different things to fix.  One tech wants me to try a DMI cable.  Have been using a VGA cable with the two screws.  I've unplugged and plugged cable back in, checked to make sure no loose cable.  Also, have uninstalled and reinstalled graphics drivers.  Dell support checked computer and could not resolve issue.

billsey

That symptom shows that the monitor decided that there wasn't a signal on the VGA cable, so it searched for signals and found it ... on the VGA cable. It can be caused by a flaky cable most often, by a video port on the computer going to sleep less often or a bad monitor/computer even less often. Start with a different cable and we'll go from there.