In for switch replacement but owner says he has , sometime back , got a
shock off the mains lead by touching the earth pin when just unplugged from
the mains.
I told him probably static discharge rather than anything to do with mains ,
but explored , just in case.
The large conventional type mains transformer is mounted on a metal plate
that is held to the wood of the casing by 4 bolts. There is no earth strap ,
or ever has been , to this plate or transformer frame, so not earthed. The 4
bolts are exposed through casing on base of the amp. Hum issue if earth
strap put in place ?


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Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/