HP41 card reader repair

[Karel]

Thanks!
I finished the repair. I used some wire insulation on motor shaft. It made the shaft almost the same diameter as the worm gear. Still smaller than the inner dia of alu tube. I then used some shrink wrap to build the diameter and connect the shaft and worm gear together. Pressed the assembly into the tube. Secured the worm gear end with tiny amount of E6000 glue.
The reader worked fine but intermittently. So I remembered what AndyGer wrote in his reply to this thread and checked the ribbon contacts. :-(

I got two 41 calc. One was halfnut CX described as for repair. It had badly corroded contacts. The other was C fullnut. Described as working. But when I got it the display was erratic. I disassembled it and used the battery connector block temporarily in the other one - the CX because it looked fine (seen from the side of battery contacts). Have not noticed the gunk on module contacts. Anyway, the infected trace seems to be cracked as well and that is probably the reason of erratic behavior after repair.
The fullnut 41C that was supposed to be working was previously heavily and not very profesionally repaired. I found the battery block glued with ca glue to back part of the case and under it broken post glued with crazy glue as well. That fell off with tiny amount of force. Lower posts where the processor board is located were smeared with superglue too and the spacer block under zebra contacts was glued to those posts. All and all bigger project than I thought.
I need to wrap new ribbon contacts around the two connector blocks first. Then repair the back case with new "improved" posts. I did not know that when I ordered the ribbon contacts from calculator store. So I am in the phase of contemplating of either placing new order or modeling and printing them myself.