Chosen Solution
A customer came in with a broken rear camera, so I switched it with a known good one, it showed a picture briefly, then purple lines down the middle, then black screen again. Reset the phone, still black screen on rear camera. Flashlight is fine, front camera is fine, and the problem started after a drop, not a repair. Thanks for any help!
Have you tried to re-install your known-good camera in a working housing? I’m curious to see if it was damaged by the original customer phone or if it works fine. That way you’d know for certain that it is not a camera issue. Doubles check the connector for damage, otherwise, you are probably facing some logic board damage which would require a micro-soldering repair.