Samsung phone enter *#0*# on the phone to test Enter *#808# on the oppo phone to test Enter *#558# on the phone to test To avoid unnecessary trouble, it is important to read the following information before purchasing. If you do not agree to the following terms, please do not place an order. If you are not a technician for repair phone, we do not recommend that you install the screen by yourself, because it is not easy to install the screen, incorrect installation can easily lead to screen damage. We will not offer the warranty to your self-installed screens. Please bring the screen to the repair shop for repair There is a layer of Screen-Protector film on it, if it has been torn off, it will not solve any problems, and there is a layer of sticker on the back, please do not tear it After receiving the goods, the screen should be tested and installed only if the test passes. If the screen detects a problem during the test, do not install it to the phone/ Pad! We should be contacted immediately to solve the problem.