The Museum of HP Calculators

HP Forum Archive 11

[ Return to Index | Top of Index ]

HP41 Card reader Malfunction
Message #1 Posted by Howard on 14 Mar 2003, 7:04 a.m.

I've successfully replaced the "gummy wheel" on my card reader. It worked for a while but after many problems it gives the message - "malfunction" both reading and writing. The book says use the cleaning card. I've done that. No good! Is there any other reason why this fault comes up? Thank you.

      
Re: HP41 Card reader Malfunction
Message #2 Posted by Stefan Hauschild on 14 Mar 2003, 8:10 a.m.,
in response to message #1 by Howard

Sometimes I have had this problem, too. First all is well but after reading a few cards or after some days it stopps working with "Malfunction" in the diplay. I my case the reader didnīt transport any card and the motor gave a weird sound. The reason was that I have not proper reassembled the motor. The two screws on the front of the motor can be used to adjust the "motor-wheel"-system. If they are not proper adjusted or if they get loose after a few cards the transporting system gets stuck. Another problem may occur if the nylon clutch that connects the axis to the motor is worn out (maybe after transporting a few cards very nice). Then you donīt get any connection and the card is not proceeding while the motor is still running. To compensate this you can take super glue instead of the clutch but then you have no "safety reserve" if the motor gets stuck. But for me this method is working well with two readers.

Hope it helps...

Stefan

      
Re: HP41 Card reader Malfunction
Message #3 Posted by Vieira, Luiz C. (Brazil) on 14 Mar 2003, 9:30 a.m.,
in response to message #1 by Howard

Hi;

I know this may be far from being the reason, but the first time I opened my card reader, I inverted to of the wires that connect the magnetic head to the control board. In my case, the message MALFUNCTION appeard and the calcualtor crashed, it was necessary to remove the batteries and then the reader. After believing I sc..d it off, I opened it again and saw the inversion. Wires back to normal position and all's weel till today (about eighteen years later...).

My US$ 0.05

Luiz C. Vieira - Brazil


[ Return to Index | Top of Index ]

Go back to the main exhibit hall