Guess I would take it apart and see if the spring came loose. Not a bad job remove seat bottom and get the screw driver to it along with I think a 1/2 inch open ended wrench.
The brake is mounted to a plate bolted to the tunnel, a cotter pin holds the whole thing to the cable.
Take it all out, clean up paint, etc.
Should not be a big deal to fix in any case is a preaty simple part.