I'm very sorry for you here. ~ I'm Samsung External Screen Replacement R, and I'm glad to answer this question for you. Here I want to tell you first, more than 95% of mobile phones have broken black screens, because the S4 screen is too thin. Although Corning toughened third-generation gorilla glass is very strong, compared with tight jeans, I think it is difficult to deal with.
The damage you think is definitely not guaranteed. Even if there is no crack on the screen of your mobile phone, if there is no crack on the screen, it is likely that the LCD screen is layered or leaking. This situation can usually be seen with a flashlight.
If your mobile phone only has a broken external screen, it won't cost that much to change it. If the LCD screen is not displayed, it cannot be repaired, and only components can be replaced. The so-called assembly is the finished product made of LCD, touch screen and external screen, which can be directly installed and used.
If the external screen is broken, it can also be replaced separately. As long as the touch function and LCD display are normal, it can be replaced separately. However, it needs professional equipment and technology instead of simple manual operation. Only professional dust-free workshop, professional equipment, experienced master and three generations of raw material mirror Kangning can change the perfect screen.
I also hope that if a mobile phone is broken, don't spend a lot of money blindly, but learn to understand. Because Samsung's high-end smartphones are almost all LED screens, although this screen is integrated, touch and LCD are integrated, but the external screen can be replaced.
I hope I can help you.