[Boatanchors] A bit OT, but we're Renaissance folks, right?

[Brian Clarke]

Hello Howard,Many electronic cameras have a memory hold-up cell, often
hard wired. The usual life in amateur use is probably 6 to 10 years.
Some camera makes use primary cells - you know the drill: when it
fails, replace it (if you can find it). Some camera makes use
secondary cells that get charged from the larger main battery when the
camera is turned on; sometimes this cell is hard-wired, too. Sounds
like your Nikon may use a secondary cell for its memory hold-up. If
you fancy your chances with tiny electronics and flexible printed
wiring, then have a go at changing the cell. I suspect the makers
decided that planned obsolescence was the better part of the balance
sheet, particularly as film use was decreasing.There are many
electronic devices that use this kind of memory hold-up system; I have
replaced such cells in all sorts of electronix equipment - fridge,
GPS, HT, camera, DVD recorder, TV set-top box, portable military HF
txvr ... 73 de Brian, VK2GCE.
Brian Clarke
BE, MBA, PhD, CPEng, FIEAust
MD, Clarke & Associates P/L

----- Original Message -----
From: "Howard Ritter" 
To:, "Leica Users Group" 
Cc:
Sent:Fri, 18 Apr 2014 17:52:19 -0400
Subject:[Boatanchors] A bit OT, but we're Renaissance folks, right?

 I have a Nikon N80 film SLR that sat unused after 2005, when I got my
first digital SLR, until yesterday. I want to use it again for an idea
I have about film astrophotography, so I put new batteries in it and
turned it on. No result—nothing on the LDC data panel, no autofocus,
no shutter, no LCD panel illuminator. Pushed the two-button reset. No
result. Batteries out, batteries in, turned it on, turned it off,
reset it, etc. etc. No result. After a few minutes I noticed that the
LCD info display on top now showed a big -E-, meaning no film in the
camera, as it does when the camera is off—progress! Turned it on and
the LCD went blank. On & off again. No result, not even the E. Another
minute or two and the E was back, and when I turned it on, it now
showed camera data, as is normal. Push the shutter button and all goes
blank. A few minutes later and the display is normal again, and now
pushing the shutter button causes the lens to auto-focus and the
shutter to fire. From there it's been working normally.

 So, as that the N80 is as much a computer-controlled electronic
device as a mechanical one, it clearly has circuitry. Apparently some
circuit component underwent a change in 9 years of not being powered
up that disabled the device, then recovered function in a gradual or
incremental manner once power had been applied. What is it?

 An internal intermediary battery that gets charged by the main
batteries, purpose being to preserve the computer's data when the main
batteries get discharged, and without a charge on which the camera
won't work? And as it charges up, starts to run the camera
incrementally? The manual makes no mention of an internal battery or
of a period of recovery if the camera's been unused for years (maybe
Nikon didn't even know this could happen).

 An electrolytic capacitor that loses its polarity in years of
non-use, then re-forms over several minutes after new batteries are
installed?

 Anyone know or have thoughts?

 —howard, n7exn

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