I just came across an old HD that I am curious to play with data recovery on. Years ago I thought it had corrupted or died and ran standard linux repair utilities on it, but it turned out that the USB cable I was using was likely the actual culprit and I fixed the drive with the faulty cable which screwed up the drive that was not actually faulty (I think). I did some searches for HD recovery but I just keep getting the generic help of run fsck and if that does not work hire it out, which is not very useful, I am not concerned about the data just want to play with trying to recover some or all of it, I don't even remember much of what is on the drive. So looking for any good resources on the topic.
From what I remember, it is an XFS filesystem, when it supposedly failed I attempted to repair it with xfs.fsck which made things worse and I strongly suspect it was actually the cable at fault which I did confirm was bad. Hindsight is great like that.
I also would be interested in ways to confirm the drives health, confirm that it was the cable that caused the issue, the drive was just a backup drive and had very low read/writes and I would not be bothered by giving up on recovering it and just formatting and bringing it back into use for backup.
Also check what SMART attributes on the drive say - it will help confirm that the drive isn't broken in other ways.
I don't know of a good resource documenting what to follow from there, but make sure you don't touch the original in any way so you can always go back.
Otherwise, look at bits separately - those are documented in various blogs - how to analyse the partitions, how to recover the filesystem, how to find binary files without the filesystem structure. Projects for reverse engineering like binwalk may also be useful here.