Volume control problem

The MX50X1 uses a series of tac switches for ch+/- vol+/- and power. It would be my first suspect. The vol- tac switch may have become thermal or what we in the industry refer to as the windex syndrome. We see this a lot on direct view TVs usually because the switching board is directly below the screen and every time someone cleans the screen with windex an trace amount of the fluid might drip all the way down to the board and invade one or more of the tac switches. This isn't the only reason a tac switch goes bad or becomes thermal sometimes it just simply fails... Tac switches are cheap (less than $2.00) but the labor to put them in is probably one shop hour. Find a good shop and have them do it - - If you're not sure where to find one goto: http://www.nesda.com/locator/state_search.php and start your research from there... Good Luck Bill PS: Impress the shop you call and tell them you think your TV has developed the windex syndrome. They'll probably think you know a lot more than you do about TV repair. :)