I came across your message while trying to look up some discrete codes for the unit in question (ie. TC-22LT1 - and still looking...). I've only had my set for only a little over 2 months and have not experienced your problem ... yet (..gulp..). However, I do recall reading some marketing material that suggested that it has a light sensor of some type in order to automatically vary its brigtness. I couldn't find any reference to that in the manual nor could I find anything on the unit that resemble a light sensor (as if though I knew what I was looking for...). I'll ask around to some folks I know who may have an answer or, at least, where to go to find some help. Let me know if you've come across any solutions.

Thanks!