Tip & How-To about Televison & Video

Magnetized TV, Poor picture, blotches, discolored, target shaped image


If your set looks like the one pictured above it is likely magnetized
and needs to be degaussed (or demagnetizing).

All CRT type TV's are prone to becoming magnetized, slowly by the magnetic pole of the earth or quickly by motors, magnets (or speakers) within close proximity of the set (5feet).
Therefore, all standard CRT type TV’s have an internal demagnetizing circuit that is engaged when the set is first turned on, after being off for the day (up to12 Hrs). If this circuit is working then you’ll sometimes hear a "bonk" sound (about 1/2 a second long when the set is first turned on) this indicates that the circuit is active.

The first thing that you could try is to remove any speakers or motors nearby the TV. Next, unplug the set and (re-plug) try again the next day (8-12hrs). If the set is weakly magnetized and the degauss circuit is working (and all external nearby magnetic sources are removed) then the set should automatically degauss and resume normal operation.

If this circuit is not working then the TV set will become strongly magnetized either over time or quickly (if magnets or motors are near the TV) and the TV will have to be degaussed with a tool, commonly used at TV repair shops called a degauss coil.
In order to properly demagnetize the TV the set would have to be brought in or a have service call booked. The demagnetizing can be done without removing the back cover of the TV but it’s best to have the technician check that the degauss circuit works in order to avoid the problem from reoccurring. The total cost of repair in shop should normally be less than $80.00.

In rare cases or if the set has been dropped or physically damaged the TV may exhibit the same symptoms. This is usually due to a broken or warped shadow mask (which is internal to the CRT) and is usually not economical to repair.


Degauss Coil

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Problem with picture color


Magnetized The set is probably magnetized and needs degaussing (demagnetizing).
All CRT type TV's have an internal demagnetizing circuit that is engaged when the set is first turned on after being off for the day.
If this circuit is working then you sometimes hear a "bonk" sound (about 1/2 a second long when the set is first turned on. If this circuit isn't working the set will become magnetized over time and will have to be degaussed using a degauss coil available at a TV repair shop (cost aprox. $35.00) and you should have the circuit checked at the same time. A set will also become magnetized if a large speaker (magnet) or motor is close to the TV. Be sure to vote/rate me if this helped Thanks!

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If the set wasn't dropped or physically dammaged the chances of it being the picture tube is very small.
The set is probably magnetized and needs degaussing (demagnetizing).
All CRT type TV's have an internal demagnetizing circuit that is engaged when the set is first turned on after being off for the day.
If this circuit is working then you sometimes hear a "bonk" sound (about 1/2 a second long when the set is first turned on. If this circuit isn't working the set will become magnetized over time and will have to be degaussed using a degauss coil available at a TV repair shop (cost aprox. $35.00) and you should have the circuit checked at the same time. A set will also become magnetized if a large speaker (magnet) or motor is close to the TV. Be sure to vote/rate me if this helped Thanks!

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Recently the picture my Sony flat screen TV has started looking quite green - does not matter if we are viewing TV or DVD - everything has a greenish hue now. Its about 5 years old and out of warrenty. Is this fixable for a reasonable cost?


The set is probably magnetized and needs degaussing (demagnetizing).
All CRT type TV's have an internal demagnetizing circuit that is engaged when the set is first turned on after being off for the day.
If this circuit is working then you sometimes hear a "bonk" sound (about 1/2 a second long) when the set is first turned on. If this circuit isn't working the set will become magnetized over time and will have to be degaussed using a degauss coil available at a TV repair shop (cost aprox. $35.00) and you should have the circuit checked at the same time. A set will also become magnetized if a large speaker (magnet) or motor is close to the TV. Be sure to vote/rate me if this helped Thanks!

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Magnetized The set is probably magnetized and needs degaussing (demagnetizing).
All CRT type TV's have an internal demagnetizing circuit that is engaged when the set is first turned on after being off for the day.
If this circuit is working then you sometimes hear a "bonk" sound (about 1/2 a second long when the set is first turned on. If this circuit isn't working the set will become magnetized over time and will have to be degaussed using a degauss coil available at a TV repair shop (cost aprox. $35.00) and you should have the circuit checked at the same time. A set will also become magnetized if a large speaker (magnet) or motor is close to the TV.

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1 Answer

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Magnetized The set is probably magnetized and needs degaussing (demagnetizing).
All CRT type TV's have an internal demagnetizing circuit that is engaged when the set is first turned on after being off for the day.
If this circuit is working then you sometimes hear a "bonk" sound (about 1/2 a second long when the set is first turned on. If this circuit isn't working the set will become magnetized over time and will have to be degaussed using a degauss coil available at a TV repair shop (cost aprox. $35.00) and you should have the circuit checked at the same time. A set will also become magnetized if a large speaker (magnet) or motor is close to the TV.

Sep 22, 2009 | Televison & Video

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