It might be broken. I had to scrap my second DS when this happened after about 2 years of use.
If a white screen is displayed, one should contact the company that manufactures the device that the White screen appeared on. Additionally asking friends who may know the answer will help you find out more about white screens.
What white lines?
A steady blue flame with no white or yellow flickering.
Single broken white lines?
One answer would be White Phosphorous. There are others.
The so called LED screens are not trully LED screens. They are simply LCD screens but they have white LEDs for Backlight.
There are 60 white lines in a mile if the lines are spaced at a standard interval of 80 feet.
White Lines - Don't Don't Do It - was created in 1995.
Street lines
White phosphorus is a chemical compound that is highly flammable and can ignite spontaneously in air. It is used in various applications such as smoke screens, pesticides, and in military munitions for its incendiary properties. However, its use is restricted under international law due to its toxic effects and potential for causing severe burns.
bright yellow with white lines but some times ornge with white lines.
Two white parallel lines indicate that no passing is allowed.