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Most worn out HP65 ever - Printable Version

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Most worn out HP65 ever - Harald - 05-02-2012

I have bought a fairly cheap HP65 on ebay recently. And it turned out to be the most worn out machine I have ever seen. Unfortunately I didn't take pictures before I started repairing it.
Somebody had burnt the display with a cigarette, the case was held togather by tape and it was really dirty. Most of the metal "click" strips (how do you call those?) on the keyboard had broken.
So I replaced the burnt display by one off an old and broken 45 which I made to fit, replaced the broken parts of the keybord with ones from the same 45 and cleaned everything. I then did the card reader repair. And I even get it to work occasionaly. But even the card reader has seen that much use, that the brushes on the Motor have worn out and it often will not start. Has anyone ever attempted to fix that? I suspect even if I manage to open the motor, I wont't be able to replace the brushes. The calculator won't become a beauty anyway, but at least it fully works now - apart from the card reader, and that is bugging me :)

Re: Most worn out HP65 ever - Matt Agajanian - 05-02-2012

Cigarettes can't be good for anybody (even a calculator). Sorry, couldn't resist. Besides, in all the application programs I've seen for any programmable calculator (even a TI-59 or SR-52), I've never seen a 'Cigrarette Smoker' program. So, I don't think you can teach a calculator to smoke.

Edited: 2 May 2012, 5:18 p.m.

Re: Most worn out HP65 ever - Hans Brueggemann - 05-02-2012

harald, if the brushes are defunkt, the motor will not start in any case. try to clean all card-activated contacts with isopropyl and test it again.

Re: Most worn out HP65 ever - Ethan Conner - 05-02-2012

Over the years i have seen many people teach electronic devices to "smoke". However this usually causes a fatal malfunction. That's a question i used to always ask pilots and engineers "did you let the smoke out"?

Re: Most worn out HP65 ever - Harald - 05-03-2012

Magic Smoke - actually, that is how electronic devices work.
And the proof is, they stop working when you let the magic smoke out :)

Re: Most worn out HP65 ever - Harald - 05-03-2012

I have connected the motor directly to the battery. It will start as soon as I turn it by hand a little bit. When measured with an Ohm meter, it will sometimes show several kOhms and sometimes 2.5 Ohms.

It's definately not the contacts that have a problem.

Re: Most worn out HP65 ever - Etienne Victoria - 05-03-2012


You have mail.


Re: Most worn out HP65 ever - Harald - 05-03-2012

No I don't. Something must have gone wrong. Try "h dot pott at gmx dot net" or "harald dot pott at gmx dot de".