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Full Version: HP11c showing all eights, won't shut off....
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Anyone seen this and maybe have an easy fix. -8's showing with all text below as soon as betteries are put in. Battery power blinky not showing. On key will not shut off unit.

Tried the shorting trick as well as reset keystrokes, same issue. Batteries go in, display all 8's and will not power down....

Sounds like ESD damage. Short the battery terminals for at least a few minutes. If it doesn't work after that, it's probably toast.

I've repaired a fair number of Voyagers (with assorted faults) by carefully resoldering the 2 ICs. Dry joints seem to be quite common on those machines.

Of course you need to be fairly good at soldering (these are PQFP packages, closely spaced connections), and you need to take ESD precautions, but it is possible to do it.

Hi, Eric;

just to make sure. You wrote:

Short the battery terminals for at least a few minutes.
The original Voyager manuals actually recomend to briefly short the battery terminals with the batteries installed in the calculator. I remember a big thread with the subject, where ESD might be avoided if the batteries where kept in place, so the maximum of 4.5Vcc would remain, and the circuitry would be protected. If the short is brief enough, battery life would not be significantly reduced as well.

(In time: any news about that other subject?)

Best regards.

Luiz (Brazil)