I bought a used Sanyo DS27930 television for a 2nd tv and there are faint
whitish lines running through the screen when I watch [digital] satellite
through the coax, also a steady hum. It doesn't happen on component or
composite. The picture on coax also isn't as good as the other two. I
never noticed the problem on my old 20" TV.

I've had one person suggest it was a bad tuner, while another suggested
it's a ground loop. I'm not sure how to fix a ground loop problem on a
satellite coax but I suspect that would be the easiest to try first.

Rick