Now that I am focusing more and more on the HP41CL, it is time to get rid of otherwise perfect working HP41CV and CX, that cannot be converted to HP41CL status.
The reason for these models not being able to be transformed to CL is that they are half-nut models. That is, the processor and rest of the circuits are on a single board, as opposed to the initial models, called “full nut”, where there were two circuits. Precisely these 2 circuits made them less robust, since both circuits were not soldered together, even not slotted one into the other (like a computer board), but joined by pressure. The screws that closed both shell halts were responsible for that pressure. Any broken screw post (the know weakness of the HP41c) would not affect in principle a half nut model, while it would bring a full nut to a halt.
This is the reason that sometimes I dare to buy a non-functioning full nut in good physical state: there are good chances that the sole defect is a bad connection of both circuits, and this is solved by repairing the screw posts only.
Both machines on sale are tested, without rust in the battery contacts, and in perfect shape. All of them have the keyboard click that made HP famous.
Here are the links to both models in our webshop: