Need help: Restoring HP41C

From: Joe <>
Date: Fri Oct 24 21:00:30 2003


  I used to repair HP -41s. I cut shims out of old punch cards and slid
them between the elastometric foam and the flexible conductor then cut the
ends off. The really impostant thing about the 41s is that the screws and
the posts that they screw into must be in good shape. Also the plastic
around the hole where the screw goes through the back case. If any of those
are broken or stripped you won't be able to make the 41 work reliably. When
assembled, you should not be able to readily pull the case halves apart. If
you can then that's your problem.

   DON'T OVER TIGHTEN THE SCREWS!!!!!!!!!!!!! Clamp the case halves
together by hand and tighten the screws until they just seat. If the
contacts are unreliable then there are other probblems, fix them, don't
overtighten the screws. If you do then sooner or later the back will break
out or the posts will break or strip the threads.

  If you want to, send it to me and I'll see what I can do with it.


At 06:28 PM 10/24/03 -0700, you wrote:
>This query would probably best be answered by any list member who works
with classic calculators.
> I have an HP41C in pretty decent condition. The problem is that, over
time, the rubber pads under the flex circuit below the display, and the
elastomer contacts joining the logic board to the keyboard, seem to have
deteriorated enough that the thing is wildly intermittent.
> What's the best way to deal with these issues? Would I be better off
simply replacing the two elastomer strips? If so, where would I get them from?
> Thanks much...
>Bruce Lane, Owner & Head Hardware Heavy,
>Blue Feather Technologies --
>ARS KC7GR (Formerly WD6EOS) since 12-77 --
>"Quando Omni Flunkus Moritati" (Red Green, aka Steve Smith)
Received on Fri Oct 24 2003 - 21:00:30 BST

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