Comcast Tech's are idiots. My mother knows more about technology than they do. From the second pic it looks like you have the correct cable for your tv. I would assume it's the cable that was packaged with the TV? The only way you would have a 220v TV is if you lived in Europe, or purchased the TV from there. If you want to know for sure, look at the sticker on the back of the TV, as I can't see it well enough in the picture, and look for Input or Input Voltage. If it says anything from 110v to 125v you are good to go.