Fine tuning has greatly improved the appearance of the vertical white line, it's now only slightly visible on the darkest of screens.
I've never tuned a 405 line set before and I'm a little confused why fine tuning seems to be the same adjusting the brightness. It wasn't until the picture was very dark that it broke up or very bright before it went fuzzy. There was lots of adjustment between between the two, without any deterioration in the picture, so I went for max volume on the speaker
.
Regards
David