HP-41 Card Reader

[n1msr]

Firstly, thank you to all who replied. The links to 41 card reader threads in this forum helped me understand that I need to check the alignment of things in the card reader. I had seen the HP maintenance manual but was originally put off by the poor quality images. However, in one of the forum threads, someone (Marco?) posted really nice photos, so going back to the HP "official" guide would be possible.

My 41 card reader did work fine for many years after I acquired it in the late 1990s. The forum thread (Ignazio/Diego/others) provide plenty of food for thought and things to try.

One important bit of information I did not include was that before I dis-assembled the card reader to clean the gummy wheel and replace with o-rings, I did get an error (don't remember the message, apologies) on the calculator and I heard the motor seem to try to run very briefly. But it did not pull the card through at all.

Post o-ring repair, the connection of the card reader to the calculator does not seem to be acknowledged by the calculator at all. But the motor itself does work and as mentioned, pulls the card through nicely.

So something(s) seems as if it is not connecting correctly. I do not have any other modules in the calculator. I don't own any HP-41 modules - althought the one mentioned in the HP maintenance manual sounds like it could be worth having!

QUICK UPDATE: I sometimes get a brief (very short) sound of the motor and the message "MALFUNCTION" and then "CARD" in the 41 display.

Thank you.

Mark