Hoser34 Said:
"iphone 12 cameras show black screen: On my iPhone12 when I open the Camera App it only shows a black screen. It doesn't matter front or rear camera. I tried restarting, updating the iOS and a few other things I found in these community postings. Any other suggestions?"
-------
Troubleshooting a Black Camera App:
A. First, Go Here: If the Camera or Flash on your iPhone, iPad, or iPod touch isn't Working - Apple Support
B. Uncover the Camera:
Is there anything covering the camera? If so, remove it.
C. Any Ungenuine Camera Message?:
Did you recently get the camera replaced? If so, contact the person(s) who performed the replacement, and have them place a genuine camera in there.See Here: About Genuine iPhone Cameras - Apple Support.  They should have known better.