Maybe a fix?
I think I may have fixed mine, on a Samsung UN40C7000 set.
After taking the rear cover off, and putting on rubber gloves so as to not short out anything with my fingers, I noted carefully that the red half screen would come and go depending on how I flexed different parts of the video board or the TV as a whole.
Looking down at the small crevice between the board and the aluminum back, I noted that there were what appeared to be foam pads on the back of the board. And when I pressed the board so that the pads were making good contact with the aluminum, the red went away.
So I unplugged the set, disconnected all the leads to the board, and took it off.
I found that there were three of these pads -- attached to the back of the video board or the aluminum by a VERY mild adhesive (I could readily pull the pads off) -- and the pads were NOT properly aligned with the white squares marked on the video board. The pads also had indentations from the surface-mount devices on the back of the board. So I rotated the pads so that the SMDs would hit un-indented parts of the pads, placed the pads carefully on the board so as to match the lines, and reassembled.
No half-red screen.
Now it's entirely possible that the problem here is the board itself, and all my moving around of pads merely made it so that the poor connection that is at the heart of this problem on the board is held in a connected state. But for the moment we have our TV back.