Aporte original por: Minho ,
When you replaced your screen, did you transplant the front camera and sensors to the new screen or where they part of the replacement screen? Along with the camera, there is a proximity sensor and an ambient light sensor. That is the one that adjusts the brightness. If you transferred the sensors, you may have put it in incorrectly. [guide|31672|Follow this guide] to double check. If the replacement screen came with the camera and sensors, it may have a defective sensor. You could use the original one to test. Otherwise, check your connections again.