Hi:
I've got a pre-overhauled HP-41 card reader from eBay that works fine with one Fullnut HP-41C and not with another. I suspect it's a problem with that calculator, but can't figure out what it is. Here's what I've found/done:
- Inserting a card in the reader immediately results in a display of "Malfunction" followed by "Card". I don't hear the motor start at all.
- If the calculator is off, inserting a card can cause the motor to start and turn very slowly.
- A module or printer plugged into to the same physical port the reader uses works fine.
- No other modules installed.
- No other problems noted with the calculator.
- Catalog correctly shows the card reader functions.
History: I had some intermittent turn-on problems with this calculator, which I first tried to resolve by cleaning the zebra connector and all board connectors. Seemed to work for a while but eventually the problem returned. Second try was to re-solder all the display board wires which appeared to permanently resolve the problem.
I re-cleaned the board / module connection again but didn't notice any improvement in the card reader problem.
Any speculations whether this is a calculator problem or reader problem? Any suggestions for troubleshooting?
Thanks!
Bob