Any thought on the reason why the following would happened.

[Andy 1066]

A sewing machine that is 40 years old, within a few seconds of being turn on, starts to operate with out the foot controller being pressed, then there is a smell of burning in the air.

When the the foot controlled is opened up, a capacitor is found to have rupture. I would like to try to understand what has happened within the foot controller, which has allowed this machine to operate by it self, because of the failure of this one component? so it seems.

Andy 1066

 

[Tha fios agaibh]

Sounds like the capacitor which is used to mitigate arcing across the foot switch contacts shorted out. Rendering a runaway sewing machine.

 

[WHONOES]

Sounds very plausible.

 

[Andy 1066]

Thanks for your for you thoughts on this matter, I now know what the cap was there for.