Secret Code for Display Test
can anyone help me?? Dis Apple had a secret code like Samsung (*#0*#) ??
完整的更换指南，从初代iPhone、iPhone 3G、iPhone 3GS、iPhone 4、iPhone 4s、iPhone 5、iPhone 5c，iPhone 5S，iPhone 6、iPhone 6 Plus，iPhone 6S，iPhone 6S plus，iPhone 7，iPhone 7 plus，iPhone 8, iPhone 8 Plus, 和 iPhone X.
Hello: No secret code. However, the link to the APP for a screen test is in the iTunes store. As of August 23rd, 2017 you have Version 4.0.
You can test the pixels, touch, pinch, move, multi-touch on 6s and beyond.
Remember, aftermarket replacement screens DO NOT provide the moisture seals, response, and drop performance so please use Apple Care or a Certified replacement brand such as eVero. Your iPhone is worth it.
Enjoy, have fun.
Apple uses a special factory firmware called SwitchBoard to perform factory calibrations. It is NOT possible to install it without factory or service center tools, so there is no code to stare test mode because it is likely never there on retail devices in the field.