If you have the S0A00 error message it means your cable box has not yet been activated or has somehow lost its activation. If the error does not go away within approximately one hour, determine if the error message is on all your TVs, or just one, and then contact a representative can assist you. I had this Comcast ref code s0a00 issue myself.
Thanks to this page, I was able to solve this issue (May 2014)
I reset my cable box, and reconnected the cable, but that did not help. I checked for loose connections in my basement where the cable service comes in, nothing was loose at all, but maybe that helped?
The main thing I did was reset the box that feeds my PHONE line, and things seemed to be good from there.