Tweeter Problem

not familiar with your speakers, but if you can access the crossover to check if there is a fuse built in, that would be my first check, next would be to pull the tweeter and apply a signal to it to see if it produces sound. If it does, that says the problem is your crossover.

Swapping the tweeters, between cabinets, will tell you if
it's the crossover. Applying a full range signal to a
tweeter(even at low volume), without the crossover blocking
mids and lows, greatly increases the chances of damaging a
working driver. If only the tweeter is not functioning;
it's obviously not the amp. If you find that the tweeter is
working; the components to look for and inspect(in the
crossover) should be a Hovland MusiCap and a couple Vishay
resistors(though there were later, upgraded, iterations).
If you need to replace the tweeter; search, "Dynaudio
Esotar," and include the numbers, found on yours.

I think the tweeters on your speakers are soldiered to the internal speaker wires. If that's the case, you can use a multi meter to see if anything is making it to the tweeter. Just touch the 2 multimeter probes to the soldier points and see if you are getting any readings. It would probably be best to play something consistent, like white noise, and check both tweeters just so you have a reference.

Yikes!
I own the Andra 2. Just thinking of taking out a tweeter or checking the crossovers seems like a very difficult task.
Good luck!