ericgibbs said:If the double wound transformer primary 'shorted' to the transformer frame/chassis then the chassis could be at the mains potential.
The transformer would most likely continue to work OK.
This was exactly the issue in the ONE receiver I tried to repair although I did not take the transformer apart.
Class II has different meanings everywhere:
For the US, it MUST be grounded: See **broken link removed**
Doorbells, telephones, parts of fire alarms and security systems are considered class II wiring.
And then we have class II appliances: https://en.wikipedia.org/wiki/Appliance_classes
Remember, that these classes did not always exist.
Take a simple electric metal post lamp. It was probably never designed as class II. lamp cord goes through the threaded rod and in the bulb housing there is a layer of a cardboard like material between the lamp housing and where the wires connect.
Remember that the year in question is 1978.
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