I've read about a million of these threads and researched elsewhere, but am coming back to the experts here.
The issue is that the camera won't work. It says, "unfortunately, gallery has stopped." We did clearing data. We did factory resets. I replaced both front and back cameras. I flashed the factory image.
After flashing the factory image, the phone boots up with "unfortunately gallery has stopped." I tried installing an old MIUI camera that supposedly only uses the back camera. It stops. Barcode Scanner stops. Trying to start a front facing hangouts session....stops. Downloaded some selfie camera app...stops.
Going to take it apart again and check connections. Any other ideas? Maybe the replacement parts from ifixit.com were bad? Or something else...