Do not throw it out! There are only 2 things to go wrong - the plate amp or the driver. I would think the most likely situation is a bad plate amp. But even the driver can most likely be repaired by a competent speaker repair company in Toronto (surely they have at least one shop to repair all the PA speakers in the numerous clubs in the area). A quick google popped these guys up:
http://www.fabaudio.com/ . I am sure they have competition.
Consider one of the Yung plate amps that Parts Express sells (I have no idea what plate amp you currently have on this sub so I can't make a recommendation without further investigation). Mount it in a external box (ref post 19 here:
http://www.audiocircle.com/index.php?topic=135972.0 for an example and picture).
Remove the existing plate amp and bypass the wiring to the driver to a new set of binding posts you add. Replace the inop plate amp to keep the unit sealed up.
Then if you still have the problem, pull the woofer and see if it can be repaired. If it can't you can surely find a replacement woofer to fit in the cutout (people here on this circle will be happy to help you).
The cabinet is beautiful and you should try to salvage this sub if you are up to a little DIY. Best of luck!
gab