How to tell if Raidho ribbon tweeter is damaged?

Most ribbons you can see the blown ribbon. They normally just quit working. A planar sometimes will make noise when they delaminate.

If you can’t hear it, pull it, and check resistance with an DMM. If it check out, go BACK check the wires, check the XO..

Happy hunting..

Thanks so much for your advice.

According to advice from Raidho, the tweeter can be retightened by heat gun (like the video shared on Raal ribbon tweeter).

Please share your advice if ribbon tweeter will sagged after it has been used for some years, especially in South East Asia where the weather is humid and hot? How long would it last usually?

"retightened by heat gun"  Yikes!  So it's just like tightening the mylar skin on RC balsa airplanes then - right?  The benefit of RC airplanes, when you screw up, you just cut another piece and heat tack it on; on a $10K speaker, eeeeh, embarking on a DIY using a heat gun sounds like...  an air ground crewman seeing a cladding defect on a B-1 bomber, then taking the bubble gum out one's mouth and just covering it up.  Yes, just McGyver it.  Sounds good to me...  Hah!

If contemplating use a hairdryer it will provide 
as hot as required. Perhaps your nomenclature/language  
was actually a hair dryer as a "heat gun" will be much 
hotter and not recommended at all. Danger!