Hi all. I have a Roku Smart Tv and I am trying to connect it to the small cable box that was given to my from Xfinity to use in each additional room. It is a small black box with two cable cord connections and a power cord. No HDMI option. I have the cable connected from the wall outlet to the box and from the box to the Roku TV. I managed to link the Xfinity remote to the Roku TV and activated the box with my account. I used the Antenna/Tv option to find channel 3 but has no channels and when I choose the Cable In option on the TV menu it says cannot find signal. I have tried but cannot figure out how to connect the cable box to the smart tv.