How to fix an old HP41cx

[brmarcant]

(05-21-2020 03:42 PM)burkhard Wrote:  The 41 depends upon the lower two screws to clamp the top and bottom of the calculator together. But they play more than a structural role. That clamping force also establishes good electrical connection between the top and bottom via the "zebra connector". Google "HP41 zebra" without the quotes and you'll get a lot of hits including pictures to show you what I mean. Anyhow, if the screw posts (especially the lower ones, as the zebra connector sits right around these) are cracked or broken off, you won't be able to have sufficient clamping force and all sorts of gremlins ensue. The vast majority of the time, when a 41 is acting really flaky, it's because of that zebra connector and the main ultimate cause is broken/cracked screw posts which need to be repaired or replaced.

Let us know what you find.

Guys I need some help.

I opened the Hp41 and it's a real mess. The zebra that I find doesn't look like the proper one for an HP41CX.

As you can see in the picture there are 3 rows of contacts (2 long, under the connectors, and one at the center shorter) but only 2 connectors ... is it ok ? is something missing there ? (see figure 1)

On the top side there are 2 broken dents that looks like are needed to keep stable the battery connector of the battery bay. Are these dents necessary for the correct closure of the case or I can leave them ? (see figure 2)

I kindly ask for suggestions on how to proceed.

The calculator originally switched on . but I'm not sure it was full functioning.