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
Are the whitish lines single traces or bands?
Are they horiz or vert?
Are they moving or stationary on the screen?
Horiz Bands could be cause by the same thing as the hum.
Single moving traces (or multiple ones together-but not a band) could
be electrical arcing from a nearby motor or other device.
Vertical lines could be a defect internal to the TV.