I finally managed to get some life to my old 1TB Lacie (Samsung) backup disk that stopped working some time in 2013.
All it needed was a good external power supply with 12 volts. I have no idea why my VS650 wasn't powerful enough to spin it.
Now, as I'm scavenging through it, I found some files that resemble Bitcoin wallet.dat -files.
This one was promising, as the name suggests. Alas, it didn't. It wasn't completely empty, but I wouldn't consider 0.00000003 BTC (0,0014€) a huge treasure either.
Anyway. I also recovered my long lost music library, and some photos and videos of our firstborn, Leo.
So all-in-all I'm pretty glad I got the hard drive working. Maybe there'll be other things to find too, as I haven't yet gone through the entire huge unordered mess that I once called a backup.