I had this problem and it didn't matter what channel I was on. picture would cycle on and off about every minute. Rebooting the tv box didn't help. I then rebooted the modem (unplug power supply for 10+ seconds) and on first try no connection to the internet at all. On second try the modem wouldn't even come on (no lights), and I was suspecting a power supply problem. On third try the modem did reboot and everything came back and the tv channels no longer cycled on and off. It appears the modem may be defective and overheating causing this problem. I will be monitoring this until I move and upgrade.