AFAIK all lcds have a standby mode. The unit checks for a v-sync and if none is detected (cos the pc is off) then it enters standby (usually shown by an amber lamp). When v-sync returns the LCD powers on and locks to the signal to display an image. What makes you say electronics is the way to go? If it is I can help you with a basic circuit.
Update: if you’re referring to an LCD tv then things are different from a pc LCD. The unit should still enter standby if left long enough without a signal. The problem is it will not automatically come back on with the video signal. Also when it is switched on with the remote it will probably default to a tv station and not the hdmi input connector. You’ve got 2 different problems there.