The copper plate might be an EM shield for the upper head, some floppy drives have those (in various shapes) and the glue/sponge that keeps it in place just lets go. It can mess up the drive and any floppy that was in it were it to fall into a wrong place during operation. It shouldn't really affect the head operation, not by much anyway, but perhaps it already did some damage? Can you format and then read and write floppies in that drive? If so then the head is probably fine but could be misaligned now.

Deunan wrote on 2024-05-10, 17:06:

The copper plate might be an EM shield for the upper head, some floppy drives have those (in various shapes) and the glue/sponge that keeps it in place just lets go. It can mess up the drive and any floppy that was in it were it to fall into a wrong place during operation. It shouldn't really affect the head operation, not by much anyway, but perhaps it already did some damage? Can you format and then read and write floppies in that drive? If so then the head is probably fine but could be misaligned now.

I can use this drive pretty much okay, just that it won't read floppies (tries to read then I get that the disk is not formatted) formatted from 3,5" FDD's and those PC FDD's won't also read floppies (same behavior as before) formated on this USB drive. Tested this on many PC floppy drives and diskettes yet same behavior. The plate fell out when i disassembled the drive since the floppy got stuck.

You need to try floppies written by other drives (this also means floppies with drivers or software) to see if those work. Otherwise you can't be sure which of the 2 machines you use is the one with misaligned heads. If it does turn out the USB drive is misaligned you'll need a scope, and possibly some external rig to power and force the USB drive to spin (by removing the USB chip and injecting power and control signals yourself), otherwise it'd be extremly frustrating (if not impossible) trying to guess how the head should be adjusted.

Deunan wrote on 2024-05-11, 09:43:

You need to try floppies written by other drives (this also means floppies with drivers or software) to see if those work. Otherwise you can't be sure which of the 2 machines you use is the one with misaligned heads.

Thats what I did. Tried many different floppies on this usb FDD from many different 3,5" PC FDD's. Just that the USB one is only reading floppies which were formatted by itself. 3,5" PC FDD's won't read floppies from the USB one.

Yes sounds like the USB has a bad head alignment, not worth trying to fix IMHO as they are $15 +/- in my area for a used one....