Chosen Solution
Hey, I somewhat recently purchased a used iPhone 8. It has this issue where the camera app is just black, on both rear photos/selfies, and the flash doesn’t work (but I know the flash works in sync with the camera). However, sometimes I can get it to work (e.g. I reset the phone twice, got on a FaceTime call, or did an iTunes update and It suddenly works - both cameras and video, FaceTime, even Snapchat images). Sometimes it will stay working or sometimes it will stop (e.g. I set it up without an iCloud account once and added it and used it the next day - the camera had stopped working. I am somewhat confused at what can be the culprit, as the cameras themselves do sometimes work, and when they do images are clear, audio is fine, and flash works perfectly, with no lag. Could it be a software thing (it is on the latest version - iOS 14.6 I think), or a motherboard IC chip issue. It hasn’t been repaired by me and True-Tone and stuff still work with some scratches and scuffs, so I don’t think the fault is a botched previous repair. I am thinking about bringing it into Apple, but that requires a trip to the City. Any ideas?
If you just purchased it I would firstly rule out a parts issue. Disconnect the front flex assembly and see if the rear camera starts working and vice versa with the rear camera. If you take it to apple they will tell you it cannot be fixed and try and sell you another phone as apple stores do not fix iPhones beyond a replacement screen or battery.
