My grandparents have a 4 room dish package and one of the receivers has a snowy screen. Deciding to help them i checked to see if the cables were in good shape which they were. Channel selector was good and and on channel 4 but it still has a snowy screen. I thought it had to be something with the input switch but that didnt help either. Technical support was baffled as well. Have to wonder whats going on here.