Television and Home Theater

I can turn TV on and after it plays awhile, I cannot shut off or adjust volume (I unplug to power off).  I had it looked at by a Sears rep and they said the signal board needs to be replaced (cost $400).  Is this difficult to do and do you know if the board cost that much?  Or is there something else that could be done?  Thanks

Hi everyone i'm having a nightmare with my tv i've plugged my freeview box into the scart socket and it lets you watch it but then every couple of minutes the tv will switch itself over to av1 then back to av2 which the box is plugged into,i've tried putting it into av1 but it still does it i cant watch any programme from start to finish and its driving me mad!!

Have three year old Gateway plasma TV. The remote and power button will turn the TV on. I hear a click and see blank TV with only an occasional flicker. No sound, no picture. The remote nor the power button on will turn the TV off.

 Does the TV need resetting? There's no button to do so. The remote has a reset button but response when it's pushed.

Rickshaw