TV Malfunction

[Robitaca]

My son put a magnet up to the tv screen and was humoured by the rainbow effect. Downside, my tv now has a shadow on the spot where he held the magnet. Can anyone advise on a way to clear this?

[gleaveyweave]

My son did exactly the same thing and a tv engineer told me that turning the tv off completely and leaving it for about 10 minutes would do the trick - and it did!
Good luck.

[Octavius]

Your son has magnetized the shadow mask that's located just inside the screen of your colour television. It is a common problem and one that can easily be fixed by "degaussing" the mask � it can take years to fade on its own. You can have it done professionally or you can buy a degaussing coil yourself and give it a try.

To demagnetize the shadow mask, you should expose it to a rapidly fluctuating magnetic field that gradually decreases in strength until it vanishes altogether. The degaussing coils mentioned above plug directly into the AC power line and act as large, alternating-field electromagnets.

As said above, many modern televisions and computer monitors have built-in degaussing coils. Each time you turn on one of these units, the degaussing circuitry exposes the shadow mask to a fluctuating magnetic field in order to demagnetize it. If your television set or monitor has such a system, then turning it on and off a couple of times should clear up most or all of the magnetization problems. However, you may have to wait about 15 minutes between power on/off cycles because the built-in degaussing units have thermal protection that makes sure they cool down properly between uses.

[saxy_jag]

This happened to us once. Some idiot (who shall remain nameless - ho-hum, whistle, whistle) put a magnet down in front of the new set. Being round, it rolled along in front of the set and we watched the colour change across the screen as it did so. However, a couple of switch-ons later, it was fine. It's still working (touch-wood) five years on.