I have a peavey tko 80 bass amp it's getting power but no sound will come out.?

I acquired a peavey tko 80 bass amp that used to belong to my uncle. He let someone borrow and when they brought it back they said that it stop working. I took it home with me, plugged it in and turned it on. You could hear it come on through the speaker and the power l.e.d. comes on, but when you plug you bass in,nothing. No sound whatsoever. Someone told me it could be a fuse or transmitter. Could it be a Blown Speaker? I also have a tko 115 and it has a fuse that you can get to from the back, but the 80 doesn't. Is there any way I can check this out myself?