Alternator seized... or something...

alternators have 2 bearings in them (or one bearing and a bushing) Its possible to crack it open and find what the issue is, probably a screw or brush piece jammed in between the stator. If it is spinning but no charge, check brushes. alternators are pretty simple, 3 moving parts if you include the 2 brushes!

Hint: the brushes can be retained in the retracted "install" position by a paperclip.