I have an Atlona 8x8 HDMI Matrix which has 3 inputs (Humax Freesat, BTVision and CCTV) and currently displaying on 3 TVs around my home. Picture is distributed via cat6 cable. I have recently tried to add another tv but am not getting any picture. The tv is Panasonic. And it shows that there is a signal coming through when plugging or unplugging the cat6 cable. I have also plugged directly into the hdmi input I intend to use. So my question is whether or not Panasonic have a feature I need to switch on or off to allow a picture to show? CEC? Viera? Can anyone advise? Thanks in advance for your help.