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What is this style of pin called?

quelgeek

Jan 23, 2020
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Jan 23, 2020
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I am attempting to refurbish an old Hewlett-Packard calculator. There are three stacked boards connected using pins as shown in the attached photo. I have been unable to locate a source for this exact shape of pin. I have no idea if it is a proprietary HP design. My problem may only be that I don't know what words to use in a Google search.
pins-medium.jpg
 

shrtrnd

Jan 15, 2010
3,876
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Jan 15, 2010
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3,876
I've never seen one before, it probably is a proprietary part (if not somebody here will correct me).
I'd try to find a maintenance manual on your calculator, or a schematic with the part number and go from there.
I don't know why you need those pins, but if I was desperate, I'd look for a junker model of your calculator on
eBay and buy it to strip parts from.
Sometimes, when you post the model of your calculator here, other members like to try to search for information
on it, and might be able to supply you with helpful information.
 

quelgeek

Jan 23, 2020
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Jan 23, 2020
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Thank you for the speedy response.

It's an HP29C.

It is hard to declare one of these old HP Woodstock calculators a junker. They are often pleasingly easy to fix. One might have to buy several before getting one truly beyond repair so one could strip it with a clear conscience! And even supposedly dead ones sell as collectors items for silly money.

Plan A is to find a source of new pins. Plan B is to replace all the pins with a modern set of interconnects. Plan C is, as you suggest, eBay diving and expecting to part with lots of money.
 

shrtrnd

Jan 15, 2010
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If you find a schematic with parts identification, you just might be able to Google the part number and find somebody with a drawer full of the pins(?).
 

quelgeek

Jan 23, 2020
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I believe the nearest currently available match to the connectors used in the HP2x (Woodstock) calculators is probably a SKEDD "direct plug-in" connector from Diehl Metal Applications. The contact element appears almost indentical.

Unfortunately they seem not to be available as individual pins.

images
 

quelgeek

Jan 23, 2020
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If you find a schematic with parts identification, you just might be able to Google the part number and find somebody with a drawer full of the pins(?).
Several HP fan-boys have lovingly created schematics, using pencils and felt pens, but they don't call out part numbers much.
HP-25-Schematic.jpg
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
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25,510
Those are definitely custom parts. Also the chips used in these calculators are profoundly static sensitive. Unless you've taken every precaution while handling the boards, your calculator is likely now dead.

In working order, these are pretty pricy items, and many work as good as they did when new. The week point tends to be the rechargeable batteries and charging mechanism that can work together to kill the calculator.
 
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