Also try this.
Degaussing may be required if there are color purity problems with the
display. On rare occasions, there may be geometric distortion caused
by magnetic fields as well without color problems. The CRT can get
magnetized:
* if the TV or monitor is moved or even just rotated.
* if there has been a lightning strike nearby. A friend of mine
had a lightning strike near his house which produced all of the
effects of the EMP from a nuclear bomb.
* If a permanent magnet was brought near the screen (e.g., kid's
magnet or megawatt stereo speakers).
* If some piece of electrical or electronic equipment with unshielded
magnetic fields is in the vicinity of the TV or monitor.
Degaussing should be the first thing attempted whenever color
purity problems are detected. As noted below, first try the
internal degauss circuits of the TV or monitor by power cycling a few
times (on for a minute, off for 30 minutes, on for a minute, etc.)
If this does not help or does not completely cure the problem,
then you can try manually degaussing.
Here's great site for ya.
http://www.repairfaq.org/REPAIR/F_crtfaq.html#CRTFAQ_038