An external Trekstor HDD (3,5") fell down and since then does not mount correctly in Windows.
Since it shows up as a removeable device instead as a harddrive, my assumption (without having seen it yet) would be that only the USB controller part could be broken. Perhaps the actual harddrive is still intact?
One could try to place the harddrive into another compatible case. I guess even though the HDD is sold in one part, there must be actually two...