HP 41 not working

[jebem]

(12-18-2017 11:40 AM)Frido Bohn Wrote:  

(12-18-2017 07:38 AM)jebem Wrote:  There was a very good reason why HP finally changed that design on the later half nut models after all.

This statement made me curious.
What did HP change in the design to make the half nuts less prone to malfunction, especially with regards to the broken post problem? (I'd like to introduce a new abbreviation for the HP41 enthusiast: 'BPP' aka broken post problem )

as far as i know, the half nuts have all the processor components integrated in the keyboard assembly, therefore reducing (but not eliminating) the probability of this broken posts issue.

Edit:
To be more detailed:
Both full and half nuts still use the power/IO block that is a cause for BPP issues. However the full nut have an additional BPP issues on the processor daughter board.

IMHO, this BPP syndrome is aggravated because not only the case plastics crack easily, but because HP decided to use 4 metal self tapping coarse pitch screws to make pressure over the processor pca and power/IO block.
If they spent more money to have used a more resilient solution with metal fixed pitch thread screws and metal nuts, this issue would probably be drastically reduced.

While we are at it, this kind of bad contact failure is not only about the BPP syndrome.
Even with good posts, bad contact can happen on both the Processor board and on the Power/IO block, due to the pressure contact design choice as an alternative to the conventional connectors. These pressure only contacts will lose the pressure over time due to its dependency to plastic/foam based elastic materials.
Conventional connectors would increase the production costs but would guarantee a much more reliable electrical connection as it maintains a constant pressure between the metallic parts involved.
There is a good reason why that old pressure only contacts have been abandoned in modern artifacts in favor of the good old traditional connectors, despite using updated materials and miniaturization.