: Dial *#0*# in the Phone app. This opens a hidden diagnostic screen where you can test individual colors (Red, Green, Blue) to identify dead pixels or use the "Touch" test to fix unresponsive areas of the screen. Samsung Members App : Open the Samsung Members app . Tap Support > Phone Diagnostics .
If you have recently replaced your screen, Samsung uses a specialized desktop tool at authorized repair centers to calibrate the fingerprint sensor and screen. galaxy diagnostics screen tool fixer