What is the black spot on the screen?

It is very likely that the screen is missing.

First, press the black spot by hand to see if there is liquid crystal flowing out. If there is, the screen is damaged.

This situation is generally that the screen is squeezed, which leads to the damage of the LED (triode) circuit inside the screen and cannot work normally; It is recommended to go for after-sales inspection and maintenance. If the judgment is artificial, it is not within the warranty period, go to the repair shop to change the screen or buy a screen module in the online shop to change it yourself. It's more expensive to exchange, but it's hundreds of dollars if it's original, and the most common one is 100.

Liquid crystal display (LCD) is a flat ultra-thin display device, which consists of a certain number of color or black and white pixels and is placed in front of a light source or a reflector. Liquid crystal displays are favored by engineers because of their low power consumption, and are suitable for electronic devices that use batteries. Its main principle is to use current to excite liquid crystal molecules to produce points, lines and surfaces, and cooperate with backlight to form a picture.

Disadvantages of liquid crystal display

Small angle of view

The visual deflection angle of early LCD is only 90 degrees, which can only be seen from the front, and there will be great brightness and color distortion from the side. At present, the visual deflection angle of liquid crystal displays on the market is generally around 140 degrees, which is enough for personal use, but if several people watch it at the same time, there will be distortion problems.

Response time is too slow

Response time is a special index of LCD. The response time of liquid crystal display refers to the speed at which each pixel of the display reacts to the input signal. If the response time is short, the image tailing phenomenon will not appear when the moving picture is displayed. This is very important when playing games and watching fast-moving images. Fast enough response time can ensure the continuity of the picture. At present, the response time of ordinary LCD on the market has made a great breakthrough compared with before, generally around 40 ms

Low brightness and contrast

Do you want a flashlight? This joke is about the brightness and contrast of LCD. Because liquid crystal molecules themselves cannot emit light, liquid crystal displays need to rely on external light sources to assist in emitting light. Generally speaking, 140 lumens per square meter is enough. There is still a gap between the parameter standards of some manufacturers and the actual standards. It should be explained here that some small-sized LCD monitors were mainly used in notebook computers, and the adjustment of two lights, brightness and contrast were not very good.

Maintenance problem

Liquid crystal "bad point" problem. Generally, LCD screens are made of glass, which is easily broken. In addition, each pixel is very small, and individual pixels are often broken, commonly known as "bad points". This is beyond repair. Only the entire display screen can be replaced, and the replacement price is often expensive.

The introduction of new products has its advantages over old products. The advantages of LCD are lightness, conciseness and environmental protection. However, due to the defects mentioned above, LCD products can not meet all the needs of consumers. Under the premise of such product technology, we appeal to consumers not to blindly follow the trend, but to recognize their own needs and product characteristics and make the most objective and practical choice.