A black line on a mobile screen often indicates a hardware issue, such as a damaged display or a malfunctioning connection between the screen and the device. This can result from physical impact, moisture exposure, or manufacturing defects. If the line persists after restarting the device, a screen replacement may be necessary. It's best to consult a technician for proper diagnosis an... https://smartphonecrunch.com/black-line-on-mobile-screen/