I have a Sony Bravia TV Model 46EX400. This TV will not turn off. I used the remote and the off on button located on the television and neither will shut this TV off. Also, the volume remains in a fixed position and cannot be increased or decreased. I tried using the remote and also tried using the switch that is located on the TV, neither was able to increase or decrease the volume. Any guesses as to what I could do to fix this problem ?