Why Do Magnets Destroy Computer Screens?

Magnets cause color distortions on older computer screens.

Older TV screens and computer monitors become warped when magnets are placed on or near them. This is due to minuscule, electrified phosphor lumps that coat the inside of the screen.

Effects

Placing a magnet near a computer screen will cause color distortions that look like rainbows. Moving the magnet causes the distortion to change color and shape.

Function

The inside of the computer screen is coated with tiny lumps of phosphor that glow when electrical current hits them. Three colors of phosphor---green, red and blue---combine to make up all the colors displayed on a normally functioning computer screen. Putting a magnet near the screen diverts the electrons and causes the wrong lumps to light up, creating the distortion.

Warning

Leaving the magnet near the screen for too long makes the bits of phosphor become permanently magnetized. The distortion will never go away, which destroys the computer screen.

References

• Bryn Mawr College: Magnets and Televisions
• The Naked Scientists: Why Does Touching a Magnet on a Computer or TV Screen Turn it Different Colours?