I have a Magnavox 50ML8105D 50 in. HDTV DLP TV. It powers on fine but the controls won't work from the remote or the buttons on the front of the TV. It won't even turn off without pulling the plug. This does turn off the TV and then the power button and remote can both turn the TV on but nothing else will work. I can see the normal indication of the input source so I think the bulb is fine. Any ideas of how to correct this problem?