Thanks - yes the TV does work with the cable box. The cable box uses a five pronged chord (sorry I don't know the terminology.) All my other inputs use a three (red, white, yellow) chord.
When I hit the tv/video button on the tv remote, it comes up with video 1, video 2 and input 1 (where I've connected the devises) but the screens are all black.
Sure would appreciate any ideas. I feel like it could be some crazy setting on the tv, but I did spend an hour with someone from Panasonic, and they said it was not a setting.