I have the xfinity wifi self-install kit. It has a coax cable for the modem, and there is no signal when I plug it into either of my coax cables inside. Both of these are male ends, so I bought female adapters. I went to the splitter outside and everything is plugged in. I tried plugging the modem right into the coax input outside and still nothing. I had to use an adapter here as well. Can my coaxial cable be turned off somehow? My house is wired for ethernet, but the xfinity seems to necessitate coax. I have been trying to figure this out for two days and am at wit's end.