Bad input board would be my guess. Power cycling isn't going to do anything. Are all inputs affected? Component, composite S-video (if it has that)?
Start by getting a Service Manual. have you read through the "sticky" at the top of the page?
Abundant OTA television is what makes this country different from all others. Lets keep it this way. If you like Wi-Fi so much, OTA fits right in. After all, it is wireless.