Sorry Pete. Switch off and disconect from the mains. Remove all the retaining screws from the rear of the set. 7 in all. Remove the other two screws adjacent to the Arial conector and one standing alone. This will release the back. Place the set face down on a flat surface on a towel or similar. Lift off the rear housing. BE VERY CAREFUL NOW. Youi will see that there are two screws holding a microswitch. Undo them and lift out the switch. I guess that the plastic conector plate will be snapped at its smallest cross section. Superglue support and replace. If its not that then the switch would be my next best guess.
Please be careful when attempting any maintenance. Although the TV is disconnected there are still live components.
TVMAN
November 2009