How difficult is it to fix minor geometry distortions on a 27" JVC 27FA44 direct view flat tube TV via the service menu? There seems to be one or two areas on the screen where the picture seems to be either vertically or horizontally compressed (is this called linearity?). I attached a mocked up grid distortion image of the geometry distortion phenomena I'm seeing (see attached image link). I exaggerated the effect here to make it a bit more prominent, but it does get the idea across. Would I be able to correct this kind of distortion via service menu adjustments or will I need to get an ISF technician to adjust the set?