Totem Tabu Tweeter not working, help with diagnoses/repair please.


My Totem Tabu speakers have been in a box for 6 years due to living space restrictions.  I just got them out, all fired up for some listening, and found that one of them has a failed tweeter.

I would love some help on how to diagnose the problem and find a solution, likely a new tweeter.  Or could it be the crossover? I am an electrical engineer so I know the lingo. I don't want to rush into taking them apart without getting some advice first... such as, what's the best way to take them apart?  Do start at the front (tweeter) or the back?

Thanks.
topnotchrally
To add to the weirdness, I got out another set of speakers, also in storage for 6+ years.  These are Energy ESM-2s's.  I connected them up and neither tweeter worked!  Disappointing!  I cranked it up anyway, for a laugh, and both tweeters started working! 

Any ideas?
Not that anyone seems to care but....

I have determined that the tweeter has failed/broke.  I connect the tweeter input to another speaker and that one worked, so the crossover is fine.  I've bought two NOS Dynaudio tweeters on eBay.  I was tempted by the chinese copies but stumped up for 'Made in Denmark'.

Soldering them in should be interesting as there's very little extra wire.

PS my ESMs are still working fine :-)
Those tweeters have ferrofluid. After sitting for a while, this fluid can become sticky like glue. Tweeter can be disassembled, cleaned, and new fluid refilled. Cranking the volume sometimes gives them enough of a kick to get unstuck. But you can also burn out the coils like that. You should check the continuity of the tweeter with an Ohm meter.