Yes - the issue I had was also with the tuner in the TV. It has a built-in QAM tuner (used for tuning and decoding the digitally broadcast cable channels). The problem I had was that, one day, the digital channels stopped working. I got sound but no picture on them. Analog channels were fine. Unplugging the tv from the AC power somehow restored correct functionality.
I thought to try this after reading that someone in my area who was using a cable card in their tv experienced the same proble, They were told byt he cbale company that some signal that had been sent over the cable had somehow disabled something int he cbale card. They were told to (somehow) reset the card. I finally figured that unplugging the tv was as close as I could get to that, since I do not use a cable card, just the QAM tuner in the tv.
I hope this helps...