Screen Test

[Birchy]

What causes internal "stains" on TV screens? Would leaving Teletext on too long mark the screen in this way?

[incitatus]

Prolonged exposure to the scanning electron beam will wear out the phosphor inside the screen. The only answer is to replace it. Anything where the same picture is displayed for a very long time will wear out the screen, this is why bank ATM's often have ghost images. Teletext is a prime example of this. However, strong magnetic fields will also cause a discolouration...move speakers or electric motors away from the screen