On Tue, 28 Sep 2010 08:39:00 +0100, N_Cook wrote:
Where cause is unknown I closely inspect fuses to gauge whether
mechanical/aging or thermal failure and then an idea of rupture current.

Remove the caps, smash it, grind it to dust, and then analyze it in a mass
spectrometer.

Or perhaps put a meter on it, and/or just replace it?