Volume knob seems to be properly buggered now.
Often when I turn the volume up, it jumps right down to almost silent. Careful turning clockwise used to do the trick. Now even if I spend ages turning it, the volume rarely actually goes up!! It doesn't seem to do it "all" the time, but definitely very often.
Is this a common problem? I don't know whether I can fix it, or if I'm going to have to buy something else...