Multisync Decay?
Tim,
A monitor is not something you want to go poking around in if you're not
skilled at it. Many thousands of volts in spots can send you flying. (Old
flyback joke in there somewhere.) I can't imagine how the flicker-fixer
could cause the symptom you describe, but I'm certainly no expert at those.
Any decent TV technician could measure the filament voltage for you: should
be about 6v. Is picture size correct? Did this happen all at once or
gradually? Does the dark area stay put if you rotate the display around?
Precisely which area is darker (top half, left side, etc)?
Karl