Causes
This will help determine if the problem has to do with the app you are trying to use the camera on or if the problem has to do with the camera itself. If the camera doesn’t work on the other apps, it still could be a software issue but likely not with the specific app you are using
This involves doing a teardown of the phone. Make sure you have taken a picture to know where everything is supposed to be on the phone for when you put it back together. Check to make sure the camera is connected to the bulk of the circuitry by a small ribbon cable. This is the only physical connection from the motherboard to the camera.
· Front Facing Camera Replacement
At this point the likely culprit is that the camera is faulty. If you checked the ribbon cable connection, you have already taken all the parts off you have to. Disconnect the ribbon cable and replace it with a new camera, then reconnect the ribbon cable.