I have a 85 watt Peavey Backstage amp which I dearly love, but have accidentally damaged.  Like an idiot, I left it on while I went on vacation for over two weeks.  I discovered what I had done one night when it woke me up by suddenly making an extremely loud, continuous buzzing noise.  Now that's all it does when switched on.  Obviously, something is fried from being left on so long, but I have no idea what it is, if I can fix it myself, or how expensive it will be to get fixed if I can't.  Can anyone give me an idea of what kind of damage I'm looking at so, at the very least, I don't get fleeced at the repair shop?  Any insight would be much appreciated.