All color TVs have built-in deGaussing. Each time you turn on the TV, a little bit of demagnetizing of the shadow mask (perforated steel plate) is done. It's not as strong as an external coil, so it takes many cycles to eliminate a strong magnetization.

The circuit uses thermistors, which pass current when cool, and resistance increases as the set warms up. In other words, you can't just turn the set on and off a bunch of times in a short period. Maybe once every 20 minutes, or over several weeks of normal use.

The other option is to find a deGaussing coil either from an electronics supplier, or see if a local TV repair shop will lend you one, or not charge too much to do it. Bringing the set to them will cost less, but it's better if the TV isn't moved after it's done.

If you do it yourself, you'll need to hold the coil flat with the face of the screen, a few inches away, and move the coil in a circular motion around the circumference of the screen. One word of caution: it's important to switch the coil off only after moving it many feet away from the TV, or you'll remagnetize the shadow mask with a new pattern.

Here's the results of a Metacrawler search about deGaussing.

Larry
www.fineelectricco.com