Thanks a lot for your answer and all the tips.
Trying to answer your questions. My iMac died over the weekend. I found a black screen with the "no parking" symbol on it, apparently some OS trouble. I have a current Time Machine backup, BUT there were some files I was working on (Office Word) that were not saved for a while (my bad, I know!). As far as I can see Time Machine keeps the last _saved_ version, but it does not keep the cached security versions that Word could use for auto-recovery. That is why I am trying to avoid reinstalling or rebuilding from the backup, as I am attempting to keep the hard drive as "untouched" as possible.
The iMac has a "Fusion Drive" made of a small SSD drive and a large HD. This could be part of the problem (more below).
Oh, and in case I need to specify: I am an absolute ignorant on this, I´m just trying to find all the info I can gather and play it safe. So I may be doing or assuming something obviously wrong, appologies if that´s the case.
- I tried safe mode but it did not help, went to the same dark-no-parking screen
- I have a 250Gb SSD USB for startup where I installed what I thought was a bootable OS, but turned out to be a installer--so it did not work for me (I´ll try the startup you suggested)
- The iMac starts on Recovery. It shows only the SSD drive. I don´t know whether it means that the HD is dead/unavailable or that the "Fusion drive", whichever way it works, has somehow disassembled itself and cannot see the second part.
- In fact when starting Disk Utility in Recovery mode I get a message like "Fusion Drive is down, do you want to restart it?" but it scares me to death that it may go and reformat everything (which is what I am trying to avoid) so I answer "No" every time
- I can also start from an external drive. With the help of a colleague we tried several options and in the end we managed to boot from an Ubuntu USB. Again, it did not see the hard drive at all.
Reinstalling macOS looks like the way to go, but I did not feel safe that it does indeed ignore the user data completely. If I could open it I would just take the HD out and reinstall everything, unfortunately that is not a practical option!
Once again thanks for your kind help. I´ll check the links you sent
Cheers,
A