You will most likely have to send it in to Avid.
Info on repairs is here:
http://avid.force.com/pkb/articles/en_US/FAQ/en210711
You can also call them.
Note that you do not have to buy a support code for repair issues.
Having said all that, there's a strong possibility that the minimum cost of repair and shipping might be more trouble than it's worth (vs. just getting a different interface).