Can a broadcaster control a TV receiver?

[crt89]

I was wondering this the other day. I remember how those Magnavox TV sets in schools could automatically be turned on and off from the media center when it was time to air Channel One. Somehow they sent a signal down the coax to do it. They were also somehow able to jam the channel buttons so that the channel could not be changed as well as the display button and maybe the status button also. Only the power and volume buttons would work while Channel One was airing.

I was wondering is it possible theoretically for a cable provider or a TV station to do this, ie powering on or off a TV receiving their signal or manipulating certain functions of that receiver? I am guessing that it could be, given that cable companies seem to be able to control certain aspects of digital cable boxes from remotely.

[Electronic M]

AFIK no consumer TVs have anything beyond aspect ratio controlled by the station...However cable boxes are another story. Many things on a box can be controlled by the provider. Including resets and some settings.

[Ed in Tx]

There's "UpdateTV" ...

"UpdateTV is a multipath worldwide distribution system which allows digital televisions to automatically receive firmware upgrades and software patches sent out via terrestrial broadcast, digital cable networks, and the Internet."

I suppose that's a form of taking control. Once, my 2008 year Sony HDTV had an update waiting one morning when I turned it on. No going back. Message on screen said Do Not Interrupt Power During Update Process or some such. I didn't even know it had that when it happened. It either works or crashes the TV.

[Ed in Tx]

....and I recall V.I.R. back in the '70s-'80s that was supposed to auto adjust brightness contrast color phase and level if fully implemented.