I have a Vizio 70D with the video from the cable box coming from the co-ax cable to the co-ax input on the TV. I get the channels in at 480 without a problem. However, when I add the HDMI cable from the cable box to the TV, the video becomes choppy or delayed about 1 second or so. There is no pixilation. I've tried this on HDMI 1, HDMI 2 and HDMI 3 ports on the back of the TV and the result is the same that the video becomes choppy while on the TV input. Also, the input stays at 480 and I have HD service from my cable provider, Suddenlink. I had a Vizio 70E previously in this setup without a problem but it was hit by lightning and fried the HDMI cable on the TV and the main circuit on the TV I surmise. Anyone have a problem like this? Or, better yet, a solution.