Right, quick summary is: PA speaker randomly decided to stop working one day when we turned it on. Got a pop and then nothing. After a brief panic, we found it was just a blown fuse. Went out and bought a whole bunch of matching fuses... Replaced the old one, and pop, same again... It continued in pretty much the same vein for a while, so it's not the fuses themselves. We've had this PA for YEARS! (well, 4 or 5) and never had a problem before, and one day BAM! all this. I was hoping one of you fonts of knowledge would be able to supply an answer of some description.
This is currently being blamed on me for reasons I fail to understand...