Are you experiencing a like flickering, dead pixels, or unresponsive touch areas? Self-Diagnose Your Samsung Phone
: 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 .
For truly bricked devices stuck on a black diagnostic screen, an EDL cable tricks the phone into thinking the battery is dead, forcing a reset.