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Low Battery Asterisk - HP10C
03-24-2017, 04:47 PM
Post: #2
RE: Low Battery Asterisk - HP10C
(03-24-2017 04:16 PM)John Cadick Wrote:  I just bought a 10C. It seems to work well; however, the low battery alarm asterisk is flashing almost constantly. I have put three new sets of batteries in it. The last were brand new silver oxide.

When I first installed the new batteries, the asterisk disappeared until I had done a few calculations. But then it came back with a vengeance.

In addition to replacing the batteries, I have cleaned the battery terminals in the calculator. They seem to making good contact.

I have searched the museum and the voyager series literature but haven;t found any suggestions.

Anybody have any thoughts? The serial number is 2248A11157. It is stamped USA.


That's a very old 10C, made shortly after introduction. These old ones have the battery contacts that are relatively 'flat' (vs. the later larger spring) and I've found that if battery corrosion gets into the spring contact, it can prevent good contact. Try some DeOxit contact cleaner.

Also, verify the voltage of all 3 new batteries BEFORE inserting them; if good, insert them and use the machine until the annunciator comes-on, then remove them and verify voltage again. Try to keep track of which battery was where, as another recent post reply indicated that could reveal where (which contact) the trouble is (possibly shorting).

Also, while batteries are out of the machine, short the terminals to drain any residual voltage (or is it current?) in the machine.

In the past, when I was sure I had a bad Voyager machine with same symptoms, it turned out to be only several bad batteries purchased in the same batch. Maybe you'll get lucky too.

--Bob Prosperi
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Low Battery Asterisk - HP10C - John Cadick - 03-24-2017, 04:16 PM
RE: Low Battery Asterisk - HP10C - rprosperi - 03-24-2017 04:47 PM

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