Function Test

1) Display (Backlight & Polarizing): the screen shows no dot defects, line defects nor scratches, the display brightness and picture are good.
2) Touch: sensitivity test; full touch coverage/alphabet keyboard test/3D function test/brightness display bar etc.
3) Touch Point: can normally stretch and shrink the picture with two fingers.
4) Touch ID: Check whether the home button function is normal, whether the fingerprint entry and fingerprint unlock is sensitive

Cosmetic Test

1) Cover Glass: no scratches and breakage.
2) Flex Cable: no breakage, alteration nor deformation, and the solder joints of the cable should be evenly distributed.
3) Frame: the LCD frame should not have any gaps or should not be loose.
4) General configuration: camera ring: sensor ring, ear mesh must be complete (well assembled, no distortion, no deviation)
5) Other problems that can be select out via visual inspection.

Installation Test

Uniformity test.
Proximity sensor test.
Light sensor test.
Fingerprint function test.