Even though I receive 90-100% signal strength on my OTA antenna during the test it flashes up "no signal on second tuner." Since it is plugged in the only one place do I have a defective unit? When you switch between one OTA channel and the other one is blank and the other is crystal clear. I called TIVO and she daid she thought the update would solve the problem but even though I keep forcing updates I am still on 8.1.7c. Any help would be appreciated.