"James Sweet" writes:

I've never seen a fixture with a large electrolytic across the power
line. Are you from the UK since you use the word "mains" for the

Yes, I'm in the UK.

[...]
The capacitor has nothing to do with filtering noise, it's to raise the
power factor.

I see. I had assumed it was to prevent flicker, but it doesn't
flicker with the capacitor out, so I guess not.


Your diagnosis that it's breaking down under the high voltage
is likely correct though.

Yeah, of course -- I was wondering why, though. Perhaps condensation
formed between the contacts and heated up the casing, damaging the
internals, but if so I dunno what the physical mechanism of the
breakdown is.

Thanks for your help, everyone.


John