old_tv_nut to you question, I don't know, I was thinking that the raster was shifted to the left. During setup it seemed that the raster as a whole was being moved to the left via the purity rings to get an all red screen. But maybe the right edge is just missing the picture and still receiving a black raster.
See the below video where I turned the brightness up and down, the image curves in as the brightness goes up. I can get the right edge of the screen to light up but I don't know is this raster or just light shining through?