I have TWC in Greensboro, NC and have had 2 S3's hooked up to tuning adapters for the past few months (was the first in the Triad to get one). I've had problems randomly/intermittently losing some SDV channels but could usually get them back with a power cycle.
But I went on vacation and came back to find that the house had suffered an electrical storm. A tree in the yard got hit by lightning. It ran into the house via the invisible dog fence and blew the power transformer on it even though it was hooked to a surge protector. My wireless router got hit and knocked out a couple of ethernet ports (but continued to work wirelessly) and my Control4 home automation controller is scrambled (not dead, powers on normally, but some commands are gibberish).
Well, I *think* at the same time, not sure since I was gone, I lost ALL of my SDV channels on both S3's. Can't get any of them. But all my other channels work fine, it's specific to SDV channels.
TWC came out yesterday. The tech says everything on their side is fine, TA's, CC's, etc...but he got on the phone with TiVo support. TiVo thinks their side is fine and that it's the TA's. TiVo guy actually said he had no problem replacing the S3's but didn't want to do that unless we knew the TA's were good.
Anyone have any thoughts? Seems to me that if it's specific to SDV channels that it's a problem with the TA's. Perhaps the lightning scrambled them too? Our neighbors lost their TWC boxes in the lightning storm.