I had a similar problem with my sansa mp3 players,
IF and ONLY IF you can connect to the STORAGE on it, and add a bin of the FIRMWARE can this be fixed, if not... idk...
I recommend trying to plug it into your computer and put whatever firmware bin you would use to flash it inside the mp3 player storage...
By that, I mean the one the rockbox requires before it can be installed.

That worked for me with sansa clip+ sansa fuze+, it all depends if your computer even detects it. I know on my linux OS it worked easily. Only thing is, I don't know if this will work on windows 10 or 11, so your results may vary.
Small note, I am an intermediate user of linux, I have installed arch based systems and debian based systems... That aside, though I can't give you much more info than that regarding a fix. I know very little about how to fix hardware problems aka, via flashing externally. If your storage is shot, GG...

I wish you the best on this, hope it works!