No Signal

I have a second TV with the small converter box.  The TV is now reporting no signal. I tried trouble shooting and had Comcast restart everything which has helped in the past, but not now.  Still no signal.  I tried plugging another TV into the cable to make sure it wasn't the TV's fault, that one had the same result, no signal.  I am frustrated because I have called and the call backs do not recognize my phone when I enter my reply to hit 1 or 2, so I feel lost.