DIYbanter - JVC AV-32260 right edge moves

Hello. I have had this television for four years, and have been
pleased with it so far. It is a little sensitive to magnetic fields (I
had to move my receiver and speakers way away from it to eliminate some
green spots on white fields.) I recently purchased DVE, obtained the
service manual, and adjusted it accordingly. This involved reducing
the overscan to approximately 3%. Now I noticed that the right edge of
the screen moves noticeably. On all dark screens, the right edge will
move in a distance that approaches a centimeter. On screens with
variable brightness, the scanlines which have more white are wider than
on those with more dark. Also the average level of the previous lines
affects the next line, which manifests itself as clipping the right top
corner of a letterboxed movie. Also on the overscan bounce test and
the pulse line patterns the performance is not very inspiring. I
understand from much reading that this is related to the high power
requirements of bright screens causing the beam to be weaker, resulting
in the deflection circuit being able to bend the beam away more from
the center of the screen. I also understand that this is related to
poor voltage regulation from a poorly designed or malfunctioning power
supply. My question is whether this is typical of this midpriced
$400-$500 tv? Can I check this myself with a multimeter or is this too
advanced or dangerous for a electronics novice?