Was playing my old Sunn 412lh when it suddenly stopped working all together. No sound whatsoever. It's not my head, I've been playing it through my other cab, wondering if this sounds like it would be a speaker problem or a wiring problem. Opened up the back, nothing seems to be loose. It's from the mid-70's, so maybe it just needs some new wiring? I've never blown a speaker before, so I don't know what the symptoms would be, but all of them blowing at the same time just seems implausible. Any ideas?