Chosen Solution
I replaced the screen, battery, and the power switch / LED cable on an old iPhone 6. The screen replacement and the battery went well (with the exception of the touch id button — separate issue); however, the rear facing camera stopped working. Additionally, the LED continues to be non-functional, and shows the “device too hot” warning. Of course, the device is not too hot. The power button (part of the LED cable) does function properly after replacement. I suspect I damaged something along the way — any suggestions? My next course of action is to clean and reseat the camera and LED cables/connectors.
The flash will not work if the Rear Camera is not responding. As for the “too hot” message, it sounds like one of the thermistors may have been damaged. There is a thermistor right next to the rear camera connector (see below) so you’ll want to check and make sure it’s there or hasn’t been damaged or dislodged in any way.
Basically, closely inspect the camera, it’s connector, the connectors on the board and any surrounding components for any sign of damage.
