Hey guys, I'm new here and somewhat new to bass altogether so please have patience with me and excuse any lingo I may get wrong

I've been having a problem with a bass amp combo. I think it started because of the volume being whacked up pretty high, so I'm guessing that something has probably blown.
Ever since its been making a kind of rattling sound and the notes being played are barely audible. I'll post a link to a recording I just took so you can get a rough idea of what I'm talking about.
I removed the head from the speaker that was being used and tried it in a speaker which I know works for definite, but the exact same noise is coming through, so its definitely not a problem with the speaker.
It's a fairly old thing but if the problem is fixable, i'd love to get it sorted. It's a hiwatt b30015 if that helps at all, cheers guys.
http://www.youtube.com/watch?v=c336x...ature=youtu.be