Magnetisation can cause colour splotches and similar harmful effects on your CRT (cathode ray tube) television screen. Fortunately, a magnetised TV has a degausser that may be able to fix this problem. If it doesn't work, you can use a hand-held degausser coil. Even if you have no expertise with degaussing and general television repair, you can eliminate magnetisation on your TV.
Shut off your TV. Let it cool down. You will have to wait from a half hour to a full hour. The wait time will depend on how long the TV had been on.
Turn on the TV. Every time a CRT set is turned on when fully cooled, its internal degausser will activate and reduce the effect of magnetisation. Turn the TV back off and leave it for several more minutes. Turn it back on to activate the internal degausser again. This may eradicate your display's magnetisation if the initial effect was not too profound.
Use a hand-held degausser coil if your TV's magnetisation was not effectively fixed by your set's internal degausser. Turn on the degausser coil and approach the television.
Turn on the TV. This will enable you to view the demagnetisation effect as it happens and allow you to ensure that you are performing the demagnetisation correctly.
Hold the degaussing coil right in front of the TV. Wave the coil in a circle. You will immediately notice a rainbow effect on the screen. Move the coil around the entire screen.
Step back from the screen. Continue to move the coil in a circle. Repeat this process -- moving away from the screen and waving the coil -- until the rainbow no longer appears on the screen. This will likely happen when you are about three to four feet from the TV set.
Turn off the coil. Your television should be completely demagnetised.