Wanted someone to repair vintage electronic calculators and databanks

I repaired some old HP calculators once. It wasn't too difficult as it was mostly made up of transistors, caps, transformers, buttons, hex tubes etc. It is worth your while to learn basic repair on such old beasty's.

Andrew

I don't think they are really that old.

Obviously, "old calculators" could mean many things, including mechanical. But the "digital diaries and databanks" suggest things far more recently.

I bought an HP-55 at a garage sale a few months ago, and if there are any transistors in there, they are of a limited nature.

Worn out rechargeable batteries are likely a problem. Missing chargers another. Leaked batteries that have caused outright damage to the circuitry. Keypads that have gotten dirty.

Of course, the original poster didn't give an indication of whether these things are outright dead, of merely partially operating. Dead may mean a relatively simple thing like a bad battery or on-off switch, but partially operating give clues while may be more troublesome to fix.

Obviously one should do websearches when they bring such things home. Because it can be surprising how often one can find a manual online, be it from the manufacturer or some third party. If the item has some "collector value", chances are even better of finding information, since people aren't going to bother fixing that $3.99 LCD calculator, but might find some value in keeping that 1975 calculator going, or that

1976 LED watch.

Michael

Which got me wondering

The first calculator with a microprocessor (Intel 4004 which was also the first microprocessor) was a Bowmar 910B. I wonder what it's worth? The only one I could find:

Not working... But, it might be a good deal if the CPU is still good - in the past, I've seen 4004 chips go for upwards of $100 USD on Ebay.

Post over at rec.antiques.radio-phono and you will get lots of responses.

John

I was commenting on some of the problems of older things.

But thirty year old calculators don't belong in rec.antiques.radio+phono. There's even debate, or was at one time, over early transistor equipment.

But like I said, I suspect the poster is talking about far more recent things.

Michael

Alasdair hath wroth:

I also collect HP calculators. There are quite a few web sites that deal with old calculators. My pile of calculators. Oh-oh, old photos. I have perhaps 40 LED calcs and 20 LCD calcs.

Most collectors do their own repairs. See list at:

The big problem is finding parts. Cannibalism is the most common method. If you have older HP LED calculators, be prepared to clean keyboards, rebuild the leaky battery packs, and repair the intermittent charger connector cables.

Educalc also does some HP repair:

Most of the museum sites offer links to repair services. For example, for TI calculators:

More of the same:

etc... Check the "links" pages.

--
Jeff Liebermann     jeffl@cruzio.com
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