How should we deal with iPhone touch screen failure? Since iPhone 5, Apple can only replace the outer screen (protective glass) and backlight layer for all models of mobile phones, while the touch layer cannot be replaced alone. Therefore, if the LCD screen (inner screen) is damaged or leaks, displays abnormally, etc., it is usually impossible to repair it alone, and the entire screen assembly can only be replaced. Before discussing the repair of mobile phone screens, let's briefly understand the basic structure of the screen. The screen structure of modern smartphones usually includes: protective glass (mirror), touch sensing layer, polarizing film, LCD screen and backlight from the outside to the inside. Apple has adjusted the screen structure since iPhone 5, from the outside to the inside: protective glass (mirror), polarizing film, touch sensing layer, LCD screen and backlight. By analyzing the screen structure, we can know that most smartphone screen repairs can involve replacing the protective glass, touch sensing layer and backlight. However, for iPhone 5 and later models, because the touch layer is closely attached to the LCD screen and difficult to separate, only the protective glass and backlight can be replaced. If the LCD screen (inner screen) is damaged or leaks, displays abnormally, etc., it is usually impossible to repair it and the entire screen assembly can only be replaced. Let's take the iPhone 6 as an example to discuss screen repair. According to the previous introduction, we know that the iPhone 6 can only repair the outer screen (protective glass) and backlight. The premise of replacing the outer screen is that the touch function and display function (LCD screen) must be intact, otherwise the repair will lose its value. So, when do you need to replace the backlight? If the phone has backlight problems due to water ingress, such as the screen content can still be seen under strong light, the phone can be answered normally, and there are light spots or water stains on the backlight, these situations usually need to be solved by replacing the backlight.