Originally Posted by Smooth_J
Here is another picture, but now with the lights off.
A number of owners of 2012 Panasonics have reported panels with one (or more) vertical lines on them - but primarily a single vertical line, from an inch to a few inches inside the R bezel, which seems to be the case with yours, per the pix.
Our 60ST50 came with such a line, although initially it looked like something was casting a Shadow on the screen.
After having problems with several 2011 panels, we aged the ST50 fairly rapidly (slides + other full screen material for up to 18 hours per day): the "shadow" dissipated by AROUND the 100 - 150 hour mark, leaving a Slightly Brighter line just inside the bezel - but only visible on selected gray slides.
That "bright" streak has since also vanished from view - some time between 250 & 400 hours (again, it was NOT visible during normal programming, so was not overly concerned).
Perhaps coincidentally, this panel ALSO became LESS prone to Quick Onset IR over that same usage period (250 - 400) hours, and now seems more in line with our other 2 Pan plasmas.
There have been reports from other owners stating that their panels also arrived with vertical lines that dissipated over time - hopefully yours will fall into that category, but would aggressively age during your return period: Panasonic apparently thinks that this is "Normal" (again, per owner reports...).
Best of Luck!
PS: As with many 2011 panels, our ST50 has generally become more uniform as it has aged - even beyond the vertical line.