I am having the same issue called Comcast and got no where with the representative. They tried a few things and nothing worked. their final response was I need to go get a new box at the nearest location. So not happy! Comcast robs me and for what I pay a month service should work flawlessly.
My cable box shuts completely off for no apparent reason. This dumps the guide to the "TO BE ANNOUNCED" mode. The screen goes blue and the "NO SIGNAL" dances across the screen. This happens once or twice a day......Now what???