Had lost authorization on all but local channels. In attempt to resolve home tech visit checked signal and found no problems, at some point cable card became unpaired and will not remotely repair. After some research and based on past problems believe original issue may have been billing code related. Have picked up new cable card but am hesitant to try pairing without contact with someone with cable card expertise.
There are currently many threads just like yours. Comcast has yet to provide any solutions. There are also many threads on the Tivo forums about Comcast no longer providing cablecard support. Tivo users are just stuck.
What about the inconvience to the customer? There needs to be a published procedeure for pairing and activating a cablecard. Not blindly stumbling through tiers 1,2,3,4 then finally finding someone who just might help. I first asked for an answer to this in 2008, and I am still waiting 10 years later.