Someone pointed out in the OP's newsgroup posting (alt.tv.tech.hdtv) that the degaussing circuit on this set is controlled by a micro, rather than a thermistor, and that this might be a coincidence due to a partial failure of the micro, or merely a quirk in the micro that needs to be addressed.

Hey, it's not the first time Sony stuff hasn't worked quite right with discrete codes - I still remember a DVD player where "Power Off" would cause it to turn off and then back on again, and "Power On" wouldn't do anything unless the unit was already on, where the "play" icon would appear on-screen but nothing would actually play.