[R-390] Unplug, was On or off?

[Buzz]

Gentlemen,
Back in the early '60's I worked as a Wurlitzer jukebox field repairman
in the Chicago, Ill. area.  Wurlitzer introduced their new stereo
machine early that spring with a new stereo amp and DC power supply
using diodes instead of a 5U4 and selenium rectifiers.
One night in June we had severe thunderstorms north and west of the
city.  The next day when I came to work we had several complaints of,
"no audio" so I loaded up a few spare amplifiers and hit the road to
service the machines.  As it turned out 18 machines had burned out
diodes in the P.S. and most of the machines were turned off. One tavern
owner told me that the sound went dead after a lightning strike.
When I discussed my findings with my future father-in-law, who was a
line engineer for Commonwealth Edison Co., he told me that it is not
unusual for their sub-stations see several KV spikes on the lines during
a thunderstorm and that voltage will easily jump a "off" switch and
damage the equipment.
Living in Reno, NV we quite often see afternoon thunder storms coming so
I unplug radio equipment and antennas.  I don't worry too much about the
computers because they are equipped with UPS's.  One day I had a nearby
strike and I saw sparks falling from a nearby power pole and the bang
was ear shattering.  Later that evening I attempted to use my computer
and I got a "no connection" message.  After further investigation the
modem cards on both computers had toasted resisters near the phone line
connector.
My thought is.... maybe some of your wall wart failures could have been
due to power line spikes.

Buzz