My guess is that about 90% of the time fuses go poof,
and
putting a new one
in makes the world fine again. The great factor here is how
conservatively
the designer specs the fuse, plus of course what happens to blow it.
The machine ran happily for around 10 seconds, then made a 'dying fuse'
noise. Not quite the bang my spare Mac Classic will give though - I get
lights with that one too :) And before anyone mentions it, this one is
definitely a 240V machine.