What's wrong with this T.V?

Tell them to stand near the exit of the room and turn on the tv, then immediately remove the remote from the room the TV is in, to farthest point away in the residence. That will tell you if the remote is the problem. I suspect it is. If not, go through the menus on the TV and see if they might have set sleep on in 2 minutes or something without realizing they did that.