Chosen Solution
I replaced my iPhone 7 screen with a 3rd party screen that comes with the front camera, earpiece, etc, and now when I go to use the front camera, all I see is black. I have tried this with both the pre-installed new camera assembly and the old one from the original apple screen. what am I doing wrong? this did not occur before repair. Update (03/22/2018) nevermind, a restart has fixed it with the original camera, the new one does not work.
yes, I was going to ask if you try to reset the device after installing the old one. good luck