Lines appearing on iPhone 6 screen

Lines appearing on an iPhone screen can be caused by either a software glitch or a hardware failure. To rule out software, try a force restart by holding the Home and Power buttons simultaneously until the Apple logo appears. If the lines are still visible during the boot-up process, the issue is hardware-related. This typically happens when the display data connector becomes loose or if the LCD panel itself has failed. Even without a drop, internal components can sometimes fail due to age or pressure. You may need to have the display cables reseated or the entire screen assembly replaced by a technician.