Glo HD GLOHD SD card bricked itself during charging, works with backup card, recover data?

[A random blob]

Hello dear mobileread!

Long time lurker, first time poster.

So, I have been enjoying my Kobo Glo HD for a long time now. Yesterday, I had an issue with it. I saw charging it and I unplugged it after a few hours, only to find it completely black screen, frozen.

So, I turned it off by holding the power button for 20 seconds, it turned off fine. Then when I tried to boot it, it showed no dancing squares, the screen only flashed white/black twice and remained white.

I don't want to factory reset it, because I have a lot of books in it (the SD card that was used was 32gb Sandisk Ultra - upgraded).

So, I got a random 4gb card, flashed it with original firmware and voila, it worked without any issues.

Now, is there a way to recover/fix my old card? I did a through test of the card's sectors, it's all good. Everything is still fast, the SD card isn't faulty 100%. It's just corrupted somewhere and I don't know where.

Here's a list of the things I'd like to get off of it:

1. All of my books - easy, I already have a backup
2. 2. Fonts - I already have a backup
3. 3. System version, same settings for everything - not a must, but I would really love this
4. 4. Read progress / groups - saved books.. I had about 50 groups and 1k of books. I NEED this back. Please.

Thank you gus, hopefully I'll manage to solve this

[A random blob]

Hello. I just managed to fix it. So, all blocks were healthy which led me to think that it might just be a bad SD card after all.. I said, why not, let's try another card.

So I put in a spare Sandisk Extreme, cloned the corrupted one to it and..

THE KOBO BOOTED!! Everything's back!! I can't believe this.