I recently moved back in with my parents in my old room. I used to have a TV that was connected to the cable jack, and a cat5 Ethernet jack. I used a working cable box and connected it to the cable jack and got a weak signal error. Customer support said he believes something could be wrong with the jack in the wall. I also tried connecting the router to this jack and it couldn't establish a connection. I tried the router and box on different jacks and it was fine. What would need to be done to find the source of this problem?