I've just repaired my 19 year old 41-CX which has been dead for about 4 years, by using the Fantastic Instructions on this Museum Site. Thank you very much. My problems were twofold:
1) due to broken case screw seats (not screw posts) on the back cover at the top of the calculator which of course didn't allow the internal electrical "pressure" contacts to be made; and,
2) several disconnected (but originally soldered) "spring-clip like" wire connections between the main circuit board and the circuit board right behind the LCD screen which were visibly separated by about 1 to 2 mm and easy to spot. Under a 10X magnifying glass I saw atleast another 5 solder contacts on the LCD board side of the contacts that had cracks in them (common problem with "cold" solder joints) so I resoldered them to avoid a similar problem in the future.
I don't know how many pieces of electronics that I've repaired over the years just by resoldering cracked solder joints, usually due to "cold solders joints" made with just a fraction too little heat when originally soldered, which leaves them brittle and easily cracked with time and regular equipment use and vibration.
I used a 5 minute epoxy glue and let it set for 15 hours before reattaching the two halves of the calculator, however within a half hour of using the calculator, the glued case screw seats (that little recessed piece of plastic under the foot pads that allow the screw heads to pull the back case together) came apart. Also the epoxy glue peeled right off of the both pieces of plastic. It appears that epoxy glue doesn't work that great on HP-41CX case plastic, however I may have to wait 24 hours for it to really work. I have never had much success using cyanoacrylate glues (aka "crazy glue") to work on much more than my own fingers, so I didn't use it as was mentioned in the section of this web site tittled "Repairing an HP-41 CX" as listed in the "Main Hall"
My questions are
1) Does anyone know what exact type of plastic is used to build those robust HP-41CX cases; and more importantly ?
2) Does anyone know what glue works best to fix cracks in the plastic used in HP-41 CX cases ?
Thanks