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Got a HP-41CV Half Nut as a early Christmas gift!
12-31-2015, 09:15 PM
Post: #29
RE: Got a HP-41CV Half Nut as a early Christmas gift!
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.

[Image: HP-CR-82104A_002.jpg] [Image: HP-CR-82104A_005.jpg]

[Image: HP-CR-82104A_016.jpg] [Image: HP-CR-82104A_019.jpg]

[Image: HP-CR-82104A_031.jpg] [Image: HP-CR-82104A_035.jpg]

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

[Image: HP-CR-82104A_036.jpg] [Image: HP-CR-82104A_037.jpg]

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.

[Image: HP-CR-82104A_052.jpg] [Image: HP-CR-82104A_053.jpg]

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Messages In This Thread
Half/full nut? - wojtek - 12-21-2015, 09:04 PM
RE: Got a HP-41CV Half Nut as a early Christmas gift! - jebem - 12-31-2015 09:15 PM

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