My classmate once had such a problem. He asked an expert to analyze it. He said it was because the humidity was too high that the light guide plate behind the LCD was wet. If so, it may be thrown out after 5-6 hours of startup. Another problem is that the light guide plate behind your LCD is deformed and needs to be disassembled for shaping. Let you know the simple structure of the monitor first: the component we can see is LCD, which is the so-called LCD screen. Liquid crystal itself does not emit light. If there is no backlight behind, we can see the above picture, but just like looking at the apron, the light guide plate is composed of light-emitting diodes and plexiglass light guide system. Light-emitting diodes have great power and generate a lot of heat when they work. If the heat dissipation is not good, the organic light guide plate may be deformed by heat, so that the light guide plate will not be closely attached to the liquid crystal, resulting in shadow on the display screen! Solution: Stick the liquid crystal and light guide plate tightly with adhesive tape or other super glue!