We purchased the Magnavox HDTV model 19MD359B/F7 and an HDTV antenna. The antenna never worked properly and the stations were snowy but visible. Now after June 12, we get a blank blue screen and the message "Channel Not Available." I am not sure how to scan for new stations, and I'm not even sure everything is hooked up right. We bought a new TV so we would not have this problem, but here we are with no picture at all. Please help!