HP41 Card Reader


I bought a UK 'ex-army' HP41 card reader and calculator about 10 years ago. The HP41CV still works well but the card reader has never been tried - until today with my 'new' HP41CX.

It appears to write programmes OK but does not read them back - no error message shown (brand new cards being used). When I verify the cards I get the message "malfunction".

The card reader appears to take the cards through OK - sounds OK as well (what do I know I have never heard a working one!).

When I do'Catalog 2' the message "CARD RDR 1G" lists.

Any suggestions would be greatly appreciated - should I get the screwdrivers out yet?.


Colin (in sunny Derbyshire UK)


Correct me if I am wrong but I think we can't tell if the card reader writes the card correctly. I would try cleaning the head with the cleaning card first.


Clean the cards also. Use 99% isopropyl alchohol and a soft cloth.


Pass a new card once through the reader and then look on its underside (the black surface) if it has skid marks then the roller that pulls the card through may be going soft.

look in the forum archives for repair instructions


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