On 6/2/2013 7:23 AM, John-Del wrote:
On Saturday, June 1, 2013 4:54:09 PM UTC-4, Smarty wrote:
"William Sommerwerck" wrote:

Sounds like a purity problem. Start by degaussing it.


A purity problem would NOT have black and white looking ok as reported in

the original post nor would it result in explicit color replacements as

reported.

Not true. Purity problems are most apparent when the chroma is on. If one looks carefully, the purity problem does exist in the black and white image, but it's just no where near as apparent.

Sounds like a color demodulation problem.
A color demodulator problem would cause incorrect colors, but I've never seen one cause localized errors as the OP pointed out.

Most likely the dual degaussing thermistor is either bad, or has one lead detached from the board.
I have not dealt at all with magnetized Trinitrons / aperture grills,
and only have very limited experience with magnetized conventional CRTs
but purity problems certainly were visible in the black and white images
of those needing degaussing. It did not take moving color images to
suggest purity / magnetization nor did it take careful inspection. The
other, even more confusing original post issue was the non stationary
nature of the color shifts, and the fact they were reported as moving
with the displayed image, again evidence that the problem was not a
purity problem.

I gladly defer to the experience and judgement of those who repair TVs.
My experience is limited to building a Heathkit color set a million
years ago and repairing my Advent and Kloss projectors, not using or
needing any purity control whatsoever!