For mobile phone screen test standards:
A/B Grade: Fully functional OEM LCD with few dead pixels or small backlight problem.
C Grade: Fully functional OEM LCD with big dead pixels, big backlight problem, small (yellow/gray) color marks or be changed glass.
D Grade: Fully functional OEM LCD with color dead pixels, big (red/blue) color marks, be changed flex cable or broken 3D touch cable.
Bad: Bad LCD, bad touch. (Note: We don't pay for copy LCD, except iPhone6G/6P good working copy LCD).
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