Channels breaking up or just all black? It could be a fall sun outage.
Every year late in September, you may notice 'Sun Outages", causing loss of signal, tiling and no reception at all on several channels. This can last 2 to 3 weeks and causes channels to go black for a brief period of time. Outages can last 15-20 minutes at peak times.
You may see the error messages, “one moment please, this channel will be available shortly,” error code SOAOO, or “no signal” during the time of an outage.