Got a HP-41CV Half Nut as a early Christmas gift!

[jebem]

82104A Card Reader repair

It was a smooth procedure and it worked nicely after replacing the gummy drive wheel.

Basically I have followed the HP Service Manual included in the MoHPC USB documentation.

And I had a look on some publications freely available online as well (Thank you all):
HHC 2014: HP-41 Card reader drive wheel replacement demonstration, by Geoff Quickfall
Repairing the hp 82104A Card Reader, by Dave the "lostrabbit" and Ty Rogers
HP 82104A (HP-41) Card Reader Repair, by Peter M. Geiser
HP-41C Card Reader Repair - The Short Fix Approach, by Mark Hoskins

Following are some pictures taken during the repair operation.







New rubber wheels were installed. Perfect match and excellent drive.



Final testing.
Before assembling the case enclosure (Not shown in the above pictures):
- Have checked the two switches for proper operation;
- Have adjusted the drive wheel pressure by measuring the motor current;
- Tested for good magnetic card write/read operation.