Ok, my friend found some sort of Fender Bassman 1x15 combo amp laying around at school, but it isn't working properly. No sound is coming out of the speaker itself, only a faint sound comes out of the horn. He told me that he had changed the fuse and checked the wires and it still doesn't work. Any ideas? He's thinking that the speaker is blown, but i always thought that speakers made a crackling noise when they were blown...