Here is a copy/past from my many posts back in 02/2013.
For reference: http://www.avsforum.com/t/1366158/hdhomerun-prime-owners-thread/990
Got this from SD Tech Support:
Morons gave you the wrong cards. In a Cisco/Scientific Atlanta area, you MUST use a Cisco/Scientific Atlanta CableCARD. The 2 systems are not compatible with each other. A Cisco backend can't communicate with a Motorola CableCARD and vice versa. Take the cards back and demand they give you the correct ones, and maybe 6 months of free HBO to compensate for wasting your time.
I currently have the Scientific Explorer Set-Top-Boxes so I guessing that was the tip off since the CableCards I was given are Motorola.
And this copy/paste
Went to my local Comcast store (Big Chicken). Line was almost out the door.. again.
Explained to the CSR in 50 words or less, almost apologizing, that I was not able to activate these CableCards. I mentioned that I had Scientific Atlanta cable boxes and these CableCards are for a Motorola system.
She agrees that they are the wrong CableCards.
I was not prepared to hear that.
Anyway, she said that they don't carry those CableCards at this location and that I would have to travel to either the Cartersville or Cumming offices.
She initiated, on her own, a full credit on my account going back to when I picked up the CableCards.
I did go to Cartersville to get the cards and they worked as planned.
Some years ago, Comcast took over the cable provider in my area. Thus the confusion of equipment.