Re: Waking a slumbering 475


I think what happens on eBay is that if a seller plugged a piece of
equipment in and nothing happens, they list it as “untested”. Others are
more honest and say “powers on - no other testing done” or “does not power
on - parts only”.

I have had experiences both ways with Tek equipment on eBay. A 7A26 plug-in
that was described as “powers on - displays a trace, no other testing
done”. It worked in my 7844 for about a minute before one of the tantalums
self-destructed (unfortunately taking adjacent parts with it and burning
the underlying circuit board). It certainly may have been tested but for a
very short time. Other times, I bought a couple of plug-ins (7B92A and a
7A24) that were described as “parts only”. However when put in my scope,
they both worked fine. A quick performance test of the 7B92A showed that it
was either in calibration or close to it (though I did not do all the tests
- I primarily was looking at sweep speed accuracy against a high-precision
quartz frequency standard). The 7A24 worked fine, but I would not have done
any quantitative stuff with it without calibrating it.

On Thu, Feb 11, 2021 at 13:24 Roy Thistle <>

On Wed, Feb 10, 2021 at 07:36 AM, Torch wrote:

Before giving it to me, the owner plugged it in and turned it on
That's usually what inexperienced sellers do with these old Tek scopes
(unless you can catch them before they do it.)
If it's working, I suppose they figure, they can ask more for it.
But, if it gets killed, it probably goes into the garbage, or sells for a
lot less.
I'd say, if you got one (buyer or seller)... don't plug it in, until you
check it out.

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