"Anon Imous" wrote in message
...
Your explanation is correct. Minor fluctuations from the TV itself and
the environment will eventually randomise the weak residual magnetism.
This isn't disagreement...I'm just fillling in a few details...there is
specific circuitry built into TV sets and computer monitors that exposes the
CRT to a fairly strong and rapidly alternating magnetic field that decreases
to zero over a period of about one second. This circuit is normally
activated at switch-on and, in some cases, can also be manually activated.
This same degaussing technique is used on a much larger scale to remove the
magnetic fields of submarines and military ships.

In the case of my monitor I can produce color fringes by rotating the
monitor through 90 degrees *while it is switched on*. The color fringes
disappear after a degauss. In the case of my monitor there are no nearby
fixed magnetic fields from speakers etc.

Sally