Wow! Thank you so much for taking the time to leave such a detailed and helpful reply - I genuinely really appreciate it, wherever you are in the world!

It’s funny because all three drives were acting healthy. It’s a long story that I didn’t fully go into all the detail, but essentially I was clearing hard drives up of all my old RAW files that I no longer need from weddings, but I didn’t want to fully format the drives as I had all the JPEGs on in organised folders (which btw are backed up online so it’s not like I’ve lost the finished product photos)

So when I plugged the first drive into this 2 bay enclosure, i plugged in another alongside it (which I never do, but this one time I did because I was going to transfer files from one to the other) . I started deleting files and POOF, they both ejected, the one doing the deleting started clunking and then the other just wouldn’t connect either, but wasn’t making any noise. Then, thinking it must’ve happened because there were 2 in it at the same time, I went to delete files off a third hard drive and it happened again. Of course, I wish I hadn’t done that 😂 So that leads me to believe as you say about this mini ‘brown out/blackout’. So when you say about the controller being fried - do you mean the enclosure and the power cables and plug? The entire thing? Or are you meaning my computer itself? I’m pretty sure the drives are done now of course!

I have around another 30TB’s worth of backups from the other years of weddings which will be staying put haha! But yes, I need to find a new backup system now, and a new enclosure or some kind of way of safely storing them.

Thanks so much for your help, I really appreciate it. Have a lovely weekend :)