Hi Omar_A1. Thanks for taking the time to reply.
You're on the nail with the solution, but unfortunately I'm too late to save the data.
I spoke to Apple Care yesterday for well over an hour, who eventually referred me to the local Apple Store. All to no avail.
Turns out the backup was corrupt and the data cannot be extracted (at least not economically - commercial data recovery may get it, but that would be very expensive).
The most likely cause was the phone being at capacity and therefore not able to download any updates. It was stuck on the initial iOS16 upgrade, and the point releases (now at 16.5.1) had not been installed. Collectively, this was probably causing the instabilities, which carried across to the backup, causing it to be 55Gb. (By comparison, a backup of my own iPhone (25Gb installed) was only 4Gb). To be 55Gb, the backup likely contained multiple dead end data streams.
On the plus side, what I did get out of my day's work on this (which will help prevent this happening to me again, and hopefully benefit others):
- if the phone is glitching, put it in recovery mode, plug it into Mac/PC and first follow the instructions to upgrade, not restore. Apparently, this can potentially fix the software issues whilst leaving the rest of the data (e.g. photos) intact. In my case, upgrading the system might not have been possible due to the phone being full, in which case:
- move the photos to another medium before doing anything else. Had I suspected this would go awry, I would have simply moved my daughter's photos to her Mac before I did anything else.
- if updating the software on the phone (and, as you say, ensuring the Mac is also up to date) doesn't fix the glitches, backup the phone in Finder/iTunes (note, the photos are still stored elsewhere at this point, so can't be annihilated). Take note of the backup size. If it's huge, it's probably corrupt, in which case, stop and speak to Apple Care (free to call or online chat).
- If all looks good at this point, archive the backup (which is otherwise overwritten every time a device is backed up to the same computer).
- Next, restore the phone - either by reset and erase all settings via Settings, or again, via recovery mode but this time choosing restore.
- Once the phone is restored and confirmed to be updated to the latest iOS, reload the backup.
- Finally, COPY the photos back to the phone (hopefully with some editing down beforehand), also leaving them on the computer for now.
- Assuming all now looks good on the phone. Run another back up (which won't overwrite the archived backup), just in case.
- For now, keep the photos backed up. Initially, on the computer, at least until it's clear everything is stable.
- Preferably, get an iCloud subscription to increase storage capacity to backup the photos in real time (or a free offering if, like me, that's sufficient - e.g Google Photos, at 15Gb).
- Update phone and backup to computer at least every six months or so. Additionally, online backup of photos is preferable to ensure photos added between backups aren't lost, but also because (as I now know well) if a full backup becomes corrupted, so do the photos, which can't happen if the photos are separately backed up. (Periodic backup of photos to computer would prevent the latter of course, but most can't be bothered, so best to leave it to automatic online).
Finally, I have to say that Apple Care is outstanding. Although they couldn't fix the problem, I was able to reach someone online in minutes, got an escalation callback within 30 minutes, and was referred to the local Genius Bar the same afternoon. For a phone that's almost 3 years' old, and a Mac that's 9 years' old. Neither under warranty nor bought directly from Apple. I can't think of any other brands that offer even close to that level of aftercare for their products.
Thanks again for your reply Omar_A1, and with any luck, this thread will benefit others (at least if they don't erase the phone too early in the process, as I did!).
