From: Katie
Email: katie@wass.net
I've repaired dozens of LED, VFD and other pre-1980 calculators, but haven't seen this problem more than a couple of times. In those cases the main IC was dead, unfortunately. However, early HP calculators, one Heathkit calculator and a few other manufacturer’s machines used all decimal points on to indicate low battery voltage. But in all of those the calculator was designed to keep functioning while showing the decimal points. Most of these calculators contain an adjustment pot to set the threshold voltage for this indication. I suppose that if that control circuit was defective you might get the results that you find. Can you give some examples of calculators that you have with this problem, I’m curious which models they are.
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