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(Scott Dorsey) wrote in
:

John Crighton wrote:

My 454 is "not easy" to work on and yet I see people
saying that it is. I am just wondering if you are repeating
what you have read on the internet supporting a Myth
that the 454 is easy to work on or speaking from
practical experience.

Everything is relative. If you think the 454 is hard to work on, you
should just SEE the insides of the 7000. Likewise the 7000 is a whole
lot easier to work on than the latest generation of digital scopes.

Yes,the TDS line has no schematics,no circuit descriptions in their
"service manuals".

I would like to clean the switch wafers of the main
timebase switch. My 454 is put together like an onion.
How do I "easily" gain access to this switch,
which is buried in the heart of the onion?

If the switch wafers really are bad, the easiest thing to do is to use
Cramolin with a very long spray tube. You can get it into very small
places without having to do as much dissasembly. But make sure the
contacts are tight, first. I don't see contact cleaning needed on
the scopes of this era, although some of the older ones did.
--scott

The 453/454 scopes have silver-plated switches,and I used to pull the
vertical preamp PCB,and clean the switch wafers with Tarn-X(also 500 series
scopes),followed by a thorough washing and 3 days in our drying oven.
Eventually,the switch contacts wear enough that they need replacing,or
someone skilled enough to retension all the wafer contacts.

--
Jim Yanik
jyanik
at
kua.net