Well, the cord that would be most readily visible is the one connecting the interior buttons on the backplate... volume, silent switch, sleep, etc... these are also mounted on the top right of the phone looking from the back, so that could be what your referring to. If you can pull it in and out of sleep and adjust volume, this is not the problem.
The antenna cable runs along the right side (looking from the front) so this could also be what your referring to. To my knowledge, the longer one is for bluetooth and wi-fi (anyone, feel free to correct me if i'm wrong here) and the short one controls power to the antennas and your cell service. Severing this cable can be catastrophic, but may not be your problem considering that you seem to have visuals on screen.
Sadly, however, the chances of repairing any of the ribbon cables in these units is extremely low, if not impossible for the average bear. Same goes for the antenna cables as well. You most likely only need to order replacement parts to get back to normal.
Hope some of this information helps, or at least helps you diagnose what needs to be replaced.