CAUSE: Static charge on the old type of CRT is arcing, causing errors.
CURE: Locate the band holding the CRT to the front of the Macintosh. If
the band has black tape around it, then it is the old CRT and this fix could
work. If an old CRT, put the electrical insulating washers between the
front of the Macintosh and each screw holding the CRT band. If the problem
still is not saved, search on "Macintosh General Troubleshooting" for
additional information.