My set is about 8 years old, with no problems until now. The remote wouldn't turn on the set. When I turned the set on manually, the onscreen display said there had been a power loss, and to reset the clock. The buttons on the front of the set would not let me into the menu. I also can't change the device to other components. I can change channels with the front buttons, but the internal speakers won't turn off so I can use the external sound system I have. The remote still operates the other components. I have tried the reset button. The system still acts the same. Any suggestions?