[volt-nuts] 7081 NVMfail
Bill Ezell
wje at quackers.net
Wed Apr 25 15:53:04 UTC 2012
I think the startup NVM test is documented in the service manual. I
think it tries to load from one page, if that fails, tries to load from
the other, but I might not be remembering correctly.
In any case, once you get comms working, you can examine the memory. If
it's readable at all, hopefully you can get the zener bias value, it's
the most critical. (I wrote mine down on a label and put it on the back
of my meter)
Also, if the meter comes up enough that you have front-panel control,
you can try a refresh from there. That copies the cal data from the
secondary page to the primary.
If you've lost the Zener cal constant, you've got a problem. You'd
really need a temp-controlled enclosure that you can vary over a
signficant range. The goal of setting the proper cal constant is to bias
the Zener into its best zero-delta tempco point, so in theory if you can
vary the temp, you should be able to fiddle the cal constant until you
minimize the tempco.
--
Bill Ezell
----------
They said 'Windows or better'
so I used Linux.
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