Bowers and Wilkens 803 D speaker stopped working

Bowers and Wilkens 803 D Speakere, tweeter only works on one of the speakers, none of the other speakers works. Speakers are approximately 10 years old. Other speaker works fine. Just happened. 
Sounds like the shorting bar across the bi-amp binding posts has come loose on that speaker. Just tighten everything.
Thanks, I'll give that a try.