destroy DVD's about 30-40 mins into a movie. IOW, movie plays fine for 30-40 mins, then picture starts pixelating and finally shuts down. I can see rings etched into the disc(s) and they won't play in any player afterwards. TIA for your help.

I wouldn't do any more experiments, at least on any discs you own. :) I would guess the transport is going bonkers some how and pushing the disc into some other part of the transport while it's playing. Time for a new player.

larry