Because another poster has problems with bad corner purity in a Sony TV,
this might be a good time to bring up my related problem.

I have a 36" 400-series flat-CRT WEGA. I had no problems with it until a day
when a discussion on rec.antiques.radio+phono prompted me to magnetize the
aperture grille by turning off a bulk tape eraser near it -- very near it.
(The point was to show that you couldn't magnetize the grille so much that
it couldn't be demagnetized. Yeah.)

You know the rest. I now have a permanent mostly-blue splotch at the
lower-right corner. The integral degausser has no effect, and the same bulk
eraser that created the problem will not reverse it. It's a pretty nasty
impurity (though, fortunately, rarely visible on 4:3 material, and outside
the range when 16:9 material is displayed).

I initially thought the bulk eraser had demagnetized one or more of the trim
magnets on the CRT. But that doesn't make much sense, because there's no way
a good sample of any CRT would show that much impurity before trim magnets
were applied. Likewise, I doubt that something got irreversibly magnetized.

Someone suggested that the aperture grille was damaged at the initial
demagnetizer shut-off. Any opinions about this, and if so, how the problem
might be reversed?

Thanks in advance.


As a side remark (which is for interest, not discussion), I also have a 32"
Toshiba IDTV. When purchased, it had an impurity splotch at the lower-right
corner that would not go away. I assumed it was shipping damage (this
particular model was notorious for suffering shipping damage), and lo and
behold, when I moved from my apartment to a condo, the jostling corrected
the problem. No more impurity.