My friend has an inexpensive 9-inch TV, about 6 to 10 years old. It
suddenly developed two green spots on the screen, one in the upper
right corner and one in the lower right corner.

I have a "GC Electronics Professional Degaussing Coil" and I made two
attempts to degauss the TV picture tube. After the second try the
lower green spot was just about gone, and the upper spot is much
smaller but can still be seen.

I'm going to try again next week and I would like some advice. In my
attempts so far I moved the degaussing coil around only the front of
the TV. Should I try degaussing the sides, top or back of the TV, or
might this make things worse?

Nothing unusual happened to cause the green spots. The TV hasn't been
moved in years and no magnets were placed near the TV. Any theories
about what happened?