@Linkat,
I'm just brainstorming here, but it could be that the TV is mounted so you cannot get to it and they have a laptop cable threaded out to the room. Just about any TV made in the last twenty years will have an RCA input. It's not state of the art, but it is ubiquitous for thinks like you sound machine, video games, etc. It will look something like this.
Besides that, every TV will have a cable hookup. Something like this.
If you can't get to those, you will need an RCA to VGA adapter.