Thin Lines on Picture
 

Here's a question I'm hoping any TV techs could provide some insight on.
I purchased a Sony KD-30XS955 back in November. I've noticed that when
the picture is extremely dark or when there is no signal on an input
(and the screen is black) there are some very thin lines running
diagonally across the screen. What can be causing this?

Thin Lines on Picture
 

What do you mean diagonally? There are one or two "guide wires" that
run horizontally across the tube that are meant to be there and can be
seen most easily on all white pictures.