I think you're on to something.
Hi Bill,
We turned on the TV yesterday and after a few minutes it was back to its old self. The top of the screen is still chopped off (as it has been for months or longer), but the picture was pretty good. It's very likely an intermittent bad connection where the video signal attaches to something inside the set. It's been OK for the last 12 hours or more.
We'll leave it alone for a while to see if it stays stable. When I've got more time, maybe I'll take the back off and see if there's a cold solder joint or something...
Ashton, I appreciate the 'scope offer. I was thinking of you when I mentioned not having one. :-) But the need seems to have passed now. I may contact you in the future though!
So, no new set seems to be needed just yet. If the US economy falls into recession, you'll know who to blame...
Thanks for the help, everyone!
Cheers,
Scott.