OK so part one gives the rundown on the situation. Part two is mildly more technical. But there’s nothing I did that is difficult. In fact maybe you have an issue with your mac and you are at a loss as what to do. This might provide you with an option.
This is a list of startup commands for a Intel based Macs. The one I’m interested in is the first, recovery mode. It allows you to start up your machine running a basic operating system on it. I’m not sure how basic - it can do a lot of stuff. Most importantly it can provide you with a bash shell.
So as I mentioned if I just started my daughter’s machine it would boot, it couldn’t find a drive it could use to start MacOS so it would just give us the folder with a question mark in it. My first step was to boot into recovery and then start up the Disk Utility. That showed me that there were two drive partitions available and mounted. This was good, good news. The drive wasn’t physically messed up or broken. This made sense since her issues came from a failed install, not some kind of apparent hardware failure.
So I exited the Disk Utility and under the “Utilities” menu at the top of the screen there is an option, “Terminal”. This is Apple’s terminal emulator that will give you access to a lot more tools, and the drives. I opened that and then moved over to the data drive. The path to that drive was shown in the disk utility. In the data drive was a directory called Users and in the Users directory was a directory with my daughters user name and in there were all her files.
All I needed to do was to plug in a USB drive, see what the path was to that drive and then copy the files over. It took very little time. If you never worked in bash you can get by with 3 commands. “ls”, “cd” and “cp”. It’s easy to find instructions on how to use these command, with examples, all over the web. They work pretty much just like their Linux counterparts so you don’t need to find MacOS specific instructions. (In fact ls and cp are enough but if you don’t want to keep typing long paths, you can cd down into the user directory and make things quicker to type in.)
My usb drive was called jrtosh. Apple for some baffling reason had the volumes for her drives with spaces in them. Super annoying - just know you escape them with a backslash \ and then basically I would do stuff like cp -r /Volumes/datadrive/Users/username/Desktop /Volumes/jrtosh/folder/ And it would just copy over that Desktop folder with all its contents.
The user folder has a library directory that may contain some files you need. But it will also have massive amounts of stuff you don’t need. If you want to copy the whole thing it may take a while.
That’s it. That’s what the Apple Store people said was impossible and she just had to lose her data or try going to a super expensive data recovery place. It took me maybe half and hour including the time to copy everything over.
If the drive is toast, this wont work. If the machine has deeper hardware issues it may not work. But if it’s just simple corruption of the boot drive due to unexpected loss of power or something, it could be fine.