OK, for some reason I read that as PTC when I was going through this, so I thought you were talking about the degauss stuff still. Yeah, a bad NTC might cause major problems like this, so I'll definitely check that the next time I'm working on this sucker.
Bob's website seems to indicate that this thing is essentially a clone of a k7000 (in fact, I had at first misidentified it as a Zenith k7000, so that makes sense). I'm thinking that means that k7000 adjustment criteria may be useful.