Let me start by saying I've left my television on for hours in the AV
(blue screen) mode. Could this cause burn-in?

Anyhow, he told me to simply turn the TV off whenever you're not using
it. Even if that means on and off four or more times a day. I've always
been averse to this, however, as I've (much more) experience with
computers, and know the effects it can have over time on the
motherboard and various components. So, is he right? Or, should I leave
it on a (non-logoed; cnn, fox news, etc..) channel? (esp. a movie type
channel)