I upgraded to new STBs about 3 months ago and now a majority of my HD channels either have pixelation or will not come on at all. This did happen prior to my new boxes but not as bad. A chatted with someone about a month ago and sent a signal to my boxes but did not help. I saw on this forum it may possibly be the ONT. Any auggestions becasue the HD channels I like are not even watchable.
It's a signal issue. It could be the ONT, loose connections, wiring, or splitters. Other than tightening all your connections there isn't much you can do. I would schedule a technician to come out.