hi I had exactly the same problem with exactly same t.v. take screen off wall. gently lay it face down on carpet. unscrew back-remove. dont panic do it methodically. there is a spring by on\off button - place in on position - this will make it always on. screw back up and put it back on wall. never touch on\off button again. turn on or off by remote control only! its fixed! it worked for me took me 20 mins and cost.
jan
October 2010