Erroneous dialog, Input Signal Not Found

[repoocld]

I frequently get this dialog "INPUT SIGNAL NOT FOUND, CHECK VIDEO CABLE", sometimes adding that the video will now go to sleep.  However my display is functioning just fine and all cable connections are firmly established, so the dialog becomes a minor, nagging nuisance.   (On the web are found many others who get this message, but do indeed have a display problem, but no one addresses my situation.)

I'd welcome any suggestions.  It seems remarkable that knowledgeable people show up, willing to help we dorks who just want to be comfortable "users".

[CherylG · Accepted solution]

Most of the time this is actually the only response the monitor knows- it simply realizes it has no input from the computer. Depending on when you get the message and/or how it is resolved will lead to a better diagnosis. For instance, if it just pops up when no one is actively using the machine Windows could be entering sleep mode and would no longer be sending a signal to monitor. If you get the message at startup of computer- it may indicate a problem with Windows  not starting up and sending the signal.

[repoocld]

Thank you, Cheryl, you've been quite perceptive and helpful.  It's good that there are guiding lights like you.

The dialog indeed seems to be associated with my system going to sleep.  The included caution to check my cable was of course immaterial but did lead me astray.