I recently sold a rear projection Toshiba TN50X81 (nice TV BTW) and
the new owner is getting some wavy horizontal lines and I'm hoping
someone here might help diagnose the problem.

The new owner said that the line is very faint and that it shows up
after the TV has been on for a while (1hr). The line extends all the
way from the left to the right and is about 1 inch wide and it is not
isolated to a particular place, but appears in the upper half of the
screen only.

This did not happen when the TV was at my house, so I think that
either something got bumped during the move or there is something
about his equipment causing it.

Does anyone have a clue as to what could be wrong? He has a center
channel speaker sitting on top of it (I did as well), but it is
supposed to be shielded (like mine is), and he has a power conditioner
(as did I) on the line.

Thanks!