Televisions use electrons and magnetic fields to produce color pictures on their screens. If a magnet comes in contact with the screen, it magnetizes that section of screen, disrupting the magnetic field and flow of electrons. This causes the color or picture of that area to become distorted. The solution to the problem is to reverse the polarity of the spot the magnet contacted. This demagnetizes it, a process called degaussing. Electronic repair shops offer this service at a price. However, a few common household items can do the job.
Find or purchase a hand-held power drill. Remove the drill bit from the chuck. No bit is necessary for this process.
Tape the magnet that caused the discoloration to the end of the drill. If you cannot use that magnet, use a refrigerator magnet or another small magnet. A stronger magnet will do more harm than good because it will most likely cause permanent damage to the picture tube.
Turn on the television. The TV must be on for this to work. Aim the drill at the television and stand approximately six feet away from the screen.
Turn the drill speed to high. The higher the RPMs are on the drill, the faster the magnet will spin which will repair the magnetic field quicker. Hold the trigger in and slowly move closer to the screen.
Hone in on the spot that is discolored. Stop when the magnet is no less than one inch from the screen. Do not let the magnet touch the screen -- this could cause more discoloration and will scratch the screen. Hold the drill there for a 15 seconds.
Slowly pull the drill back from the screen. The spot will be gone or significantly improved. You may need to repeat this process several times before it is completely resolved.
Things You'll Need
Modern televisions have an internal degausser that comes on when the TV powers on. Before trying a home repair, you may just want to turn the television on and off at intervals over several hours, and the problem may fix itself.
Do not put a magnet anywhere near the back or sides of the television. This could damage the picture tube. Exercise caution when using power tools.