I have a new Mitsubishi HDTV ready TV ...guy from TV company hooked it up with the Motorola dual tuner Comcast HD/DVR box. Worked fine for a day or two, then I had to call Comcast because I wasn't receiving a few of the HD Channels and they fixed it over the phone. The component cables are hooked up to the bottom row on the Comcast Box and to the series of Inputs on TV titled 'DTV'.
Now when I turn off my Box and TV, and I turn it back on some time later, both come on but no picture on TV. If I press guide on the remote I can see it etc. My TV will start working only when I begin viewing a show I have recorded to the DVR. When I exit from watching that show, the TV begins receiving signal from cable box and I can watch TV just fine after doing that.
I checked all connections and they seem fine. I tried switching to the inputs titled Component 1 and 2 but those did the same thing.
Of course this happens to me!