This seems to be a known issue, judging from this old post, but as that topic has been closed I just wanted to share my info here.
symptoms of the issue
- Main (rear) camera preview shows extreme purple-black distortion w. vertical lines (similar to this distortion, on a laptop camera)
- Standard camera app notices something is wrong and stops itself with a ‘can’t connect to camera’ error
- Most other camera apps show the same distortion issue*
- Rebooting, updating, clearing cache, and other software-based approaches don’t fix the problem.
what solved it
I opened up the phone, completely took out the camera module (unscrewing the 3 screws), cleaned the section of contacts that can only be reached by doing this (using rubbing alcohol and a cotton swab), then screwed the camera module back - making sure it was well-tightened.
In other words, the problem was either:
- dirty contacts behind the camera module (they looked clean enough, though).
- the camera module not having been screwed on tight (my hypothesis is that 3 years of use and the occasional fall loosened the module just enough to cause problems)
Good to know: The old topic I mentioned above did include posts advising to clean the 3 contacts outside of the camera module, which can be done without removing the module itself. This helped for some people, but didn’t help for me. So if you have this problem, make sure to clean these 3 contacts as well.
Hopes this helps someone with similar issues!
*interestingly, my two QR-code reading banking apps did NOT experience camera problems, which mistakenly led me to assume a driver problem rather than a hardware problem. Which it wasn’t.