I asked where they went, not what was wrong. I know they blow up. I would think the initial question would be "Where can I get it fixed?" or "Is it possible to fix this module after a fire?" I've seen speakers sold without the modules, as if someone stole them or threw them away. That's why I asked where the modules were.
First, the speaker load has everything to do with overheating the amplifier.
You are probably overloading it.
Second, It's LOUD TECHNOLOGY that markets these things, and they don't support them too much. You won't find a module for sale by itself. They will sometimes provide schematics.
However, might be repairable, post this question in: http://music-electronics-forum.com/
to find a mackie tech...this MEF has a lot of techs that can help you. http://music-electronics-forum.com/f22/