Good question. You have determined that the tweeters aren't working, that's for sure. It could be (hard to say without knowing what speakers you are talking about) that some kind of overload-protection kicked in (e.g. blown a fuse), and the tweeters are fine. It could also be (less likely since it happened in both speakers) that the wiring inside doesn't connect anymore. Most probably the tweeters are damaged, but there could be others reasons.
As for sound/no sound: if I remember correctly, you can blow tweeters in two ways. First you overheat the voice coil, and because of the heat, it tends to get a little bit bigger and won't fit the gap it is supposed to move in. That way, you should have a little sound left, along with some scraping sounds (very soft).
The other way is that you haven't damaged the voice coils, but the very thin wire that runs between the voice coil and the cable connection at the back or side of the tweeter. If that's is melted, there'll be no sound from the tweeter whatsoever.
So if it's worth replacing the tweeters? Pfffff.... there are a lot of 'if's' in your wuestion. One thing I can say is that it's fun to fiddle around, so I guess I would try it.
As for sound/no sound: if I remember correctly, you can blow tweeters in two ways. First you overheat the voice coil, and because of the heat, it tends to get a little bit bigger and won't fit the gap it is supposed to move in. That way, you should have a little sound left, along with some scraping sounds (very soft).
The other way is that you haven't damaged the voice coils, but the very thin wire that runs between the voice coil and the cable connection at the back or side of the tweeter. If that's is melted, there'll be no sound from the tweeter whatsoever.
So if it's worth replacing the tweeters? Pfffff.... there are a lot of 'if's' in your wuestion. One thing I can say is that it's fun to fiddle around, so I guess I would try it.