I'm at my wits end on this one. I am simply replacing a current cable run to my VIP722. It starts in my central box and runs directly to a wall jack and then to the 722. I am simply unhooking the current run (wall jack in the wrong place) and hooking up the new cable to a new jack. I have tried two different 50' runs of RG-6, Quad Shield cable and neither will work. Yet, I can take the new cable and connect it to the old wall jack using the old run and all works fine, so I can eliminate any breaks in my new cables. A direct connect with the new cables, however, does not work. I notice that as I reconnect the current run, I get sparks. With the new cables I get no sparks. I have tested with the current jack, thinking my new jack might be the problem. Same result - nothing works with the new cables. This seems like such a simple installation, but what am I missing?