Vertical dark shadow bar across LCD display

50-inch 1080p LCD display displays a vertical dark shadow across the center of the screen. Sort of like this person's display: Samsung UE49KU6400 shadow issue

My TV is around 6 years old, and just got this shadow about 2 days ago. It's never had any issues other than video processing issues that started around 3 weeks ago. I want to say that the 2 issues are connected, but any DIY attempts to fix it haven't worked.

Have powered on and off the TV, unplugged it and plugged it back in, & reset the TV to factory defaults. And, have tried everything else. Dont know what else to do.

How should I fix it, without spending too much money?