How to know one LCD for iphone quality is good and AAA quality? [This method could use for iphone 4/4s/5/5s/5c/5se/6/6plus/6s/6splus/7/7plus]
Display defect, touch, Frame.
When you get one LCD for iphone, use your finger to shake the frame, check it is sticky very stable or not,
Check the appearance not any scratch and broken.
Power on the Screen, Turn to the white/black/gray. Use your eyes check them carefully, until you find there are not any dot and spot.
There are two touch need to check. One the normal touch, check is it smooth and the icon will follow your finger go to anywhere of the LCD. 3D touch , use the finger to give a pressure to the screen, it will display the Pressure feedback。
If you have the LCD for phone, and didn't know how to test it. Just Try it.