Chosen Solution
when my take the selfie the black line appears on the screen. It doesn’t happen in back camera. What should I do?
It is a hardware issue, you can replace a new front face camera to fix this issue. If your phone is in warranty, go to apple store to replace a new camera. If it is out of warranty, repair it in a third repair shop or buy parts online and DIY. If DIY, you may need this tutorial: iPhone 7 Plus Front Camera and Sensor Cable Replacement
