Hi @adg764 Please check if your BIOS, Windows (1903/1909) is up to date, and drivers (video card especially) are all updated. Please confirm below points: Is the "black block" stays at the same spot all time in every applications you're using? If not, please let me know what application is running, or what action that will cause dead pixel to show up. When did it start to happen? (ex: After update/install program) Thanks!