My 722K is upstairs set up in dual mode. Sitting in open air. SW version 655. Here is the problem. I have had it about a year I think with no problems. In the past week or so, which ever TV is turned on second, the picture on the currently tuned channel will lock up and there is no audio. I can rewind, and it will start playing for a few seconds and then stop again. I can select the guide and the data is present, but when I select another channel, I get nothing. I am however able to view OTA, which is going through the 722K. Go check the other TV, and its fine. Again, it happens on wich ever one is turned on second. I have done the reset button, check switch, and a 30 minute unplug. None of those have fixed it. Any more ideas or do I need to call Dish. Thanks.