On Thu, 7 Apr 2016 20:36:07 -0400, you wrote:
New to the group, lots of great info. My usually faithful 2445B led me
down the proverbial garden path 'cuz I failed to notice the vertical
voltage scale wasn't changing when I plugged in my 10X probe. Got
myself a service manual from Artec Manuals (inexpensive, and great
quality). To make a long story a bit longer, seeing that the probe
sense lines went straight to a ribbon cable, I popped/plugged the one on
the main board P511 and all was well.
That is a great diagnostic and repair job. Start with the easy
possibilities.
Here's the question: As I am usually a "don't fix it if it ain't broke"
guy, does this vintage scope have problems with the ribbon cables? Mine
is wonderfully clean inside.
That is usually the best advice; rough and unneeded maintenance has
the potential to cause damage and old instruments may be fragile
simply do to age. This is why I do not preemptively replace *all*
solid tantalum capacitors but instead only replace those which either
were not properly derated or are suspected of being unreliable.
Aluminum electrolytic capacitors are a different manner since they
have a limited operating life; I would rather replace most or all of
them at once rather than one at a time.
Is it possible that the ribbon cable connector worked loose? I have
seen temperature cycling cause these connectors to separate from their
pin headers if they are not captive. I would at least check to see if
any others are loose.
David Hess