Re: HP-97 Card Reader - Only works sometimes


I cleaned the head with alcohol.
I also managed to leave the golden contacts open with just a little pressure needed for closing.

But still, the card passes correctly by I always get ERROR, now I don't get a success never :-S

Any ideas?


Hi, jbssm;

this is not good news, indeed; I have never seen such behavior before, I mean, worse operation/behavior after cleanning and adjusting contacts.

As for my own experience a few years ago, I had an HP82104A (HP41 card reader) with a bad circuitry. One of our contributors, Mr. G.D. (U.K.) also had a HP82104A with a problem, but in his case, it had a bad magnetic head. One of the coils was opened. Fortunately he mannaged to repair his unit by using the good magnetic head in my own reader (I have no idea where are its remaining parts today...). That card reader served at least three others with problems.

In your case, I think we could start with a checklist, if you allow us to. If I miss anything, please, guys, add to my list.

Mechanical adjustment - as you mentioned, your HP67 had the gummy wheel replaced, right? I saw at least two cases where the new gummy wheel was somehow touching the mechanics and the cards did not pass accordingly. In the HP8210A it is also possible to adjust the pressure of the pulling gear, i.e., the roll that maintains the card in contact with the gummy wheel has an excentric, adjustable axle. I'd guess you can do the same with the HP67's card reader

Electrical connections - It is possible that the flex circuit connecting the card reader to the mainboard needs its connections to be revised; are you completely sure they are all making contact? Just a suggestion. When I adjusted the contacts of my HP97's card reeader I tested the contacts by having a card pulled with a 1.5V battery connected to the small pulling motor. I saw it passes a few times to check if the mechanics were O.K., then I powered the motor just a few times till each contact was activated. I had to do this a few times to check each of them. One of the contacts, although closed when I inserted the card by hand, failled a few times. I guess that when we insert it by hand the card slightly bends inside the reader case, and maybe it closes the contacts in a forced condition. If it is pulled by the motor then you are actually simulateing the closest condition possible.

One last suggestion: does it show the same Error message when writign cards? Could you test so? And also does it show the message at the very moment the card is inserted or only after it completely passes thru? If it shows no message when writing, try reading the cards redcorded by it. If it shows the Error message when writing too, then we may still have at least one contact in bad shape.

Although I have an HP97, I can add the pictures of its card reader. Do you believe you need them?

I'm waiting from your good news. Success!

Luiz (Brazil)


That card reader served at least three others with problems.

As one of those three myself, let me say again: Thanks, Luiz!

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