Hp-67 Card reader


I have done a repair on the card reader. The calculator pulls the card through the calculator now. However it keep telling me error.
Any suggestions?


Reading or writing failures?


More or less what I do, in this order:

Make sure you have a known good card. Helps to have a working 67.

Double check all 5 of the wires from the r/w head. These can come loose easily and it's easy to miss.

Also check all the other wires attached to the PCB.

Be sure the PCB is correctly connected to the mainboard.

If that fails, open it up and check that all 4 tiny balls and the roller are in place, and also the two metal leaf springs are in place.

Try writing instead of reading to isolate the problem.

-- Dan


It fails on reading only.


A card reader that writes but does not read is almost always a bad tantalum filter capacitor (usually a small blue dipped tantalum) on the card read power line.


Do you have another 67, 97 or 41 (that is, something that can read a 67 card)? If so, try writing a card on the faulty machine and see if you can read it on the good one.

If you can't, check the head wiring, and check the head windings for continuity. There are 2 windings, IIRC, one has red and yellow wires, the other blue and orange wires (but I would have to check that in the schematics). If one winding is open, you can neither read nor write a card, and you're looking for a new head assembly (yes, I have had them fail).

The other thing to check are the decoupling capacitors on the various power lines. If one is defective, you get noise in the read amplifier from the motor. This will stop the machine from reading (although it will normally write OK).


What is the value of the tantalum?
Does anyone have the schematic?


It's the only 6.8uf on the reader board.

Schematics of the 67 and others are
available from http://www.hpcc.org/cdroms/ and are well worth the $. Thank you Tony...

Possibly Related Threads…
Thread Author Replies Views Last Post
  Reasonable price for a 41C, Quad Mem, Time, Navigation and Card reader module? Eelco Rouw 10 4,754 12-12-2013, 01:52 AM
Last Post: Eelco Rouw
  hp-67 card reader problem. Marcel Samek 5 3,227 12-09-2013, 09:09 PM
Last Post: Paul Berger (Canada)
  HP-97 card reader pinch roller axle davorin 2 1,615 09-15-2013, 08:47 AM
Last Post: aj04062
  HP-97 Card Reader davorin 3 1,896 09-13-2013, 04:21 PM
Last Post: Stephan Matthys
  HP-67 Card Reader Repair Question aj04062 1 1,502 08-08-2013, 11:15 AM
Last Post: Randy
  Hp-67 card reader: tantalum capacitor identification Ignacio Sánchez 8 3,258 06-02-2013, 07:26 PM
Last Post: aj04062
  Testing card reader motor for 65 Michae Altmann 2 1,631 03-17-2013, 09:24 PM
Last Post: Randy
  Repaired HP-97 card reader doesn't show any signs of life jbssm 6 2,664 02-17-2013, 03:15 AM
Last Post: Alberto Fenini
  HP 65 card reader problem H Fischer 3 1,538 11-24-2012, 12:11 PM
Last Post: H Fischer
  41CL and Card reader Prabhu Bhooplapur 3 1,590 10-18-2012, 07:40 AM
Last Post: Ángel Martin

Forum Jump: