Some HP 97 Questions



I got an HP 97 from eBay and I noticed some things I want to try to fix.

1. The printing is very faint - could it be a resistor problem?

2. The card reader does not write data and I'm assuming the card reader assumes all cards as clipped because it reads properly, so is their any way to by pass the write protection?

Thanks in advance,


I also have some questions,

I just got a working (tested with 3 AA batteries) HP97 with manuals, cards and pouch for 2 euros at a flea market (yes 2 euros)

But the deal is that there is no charger (the battery pack was re-done with sanyo battery) ...

Did someone near Paris (France) have a topcat charger ?

(I need to clean the card reader anyway)


Edited: 18 Sept 2011, 10:37 a.m.


Hello Olivier,

I was watching a relatively new French movie about 10 days ago. One of the characters had your full name!! How about that! I thought of you when I heard the name.




I just got a working (tested with 3 AA batteries) HP97

So the French market Topcats run on 4.5 vdc ?


The battery block is 4 1.2 V NiCd battery so 3 1.5 V AA works with the red led (charging needed) on.

It's enough to test the 97 and even the printer.

I dismantled the card reader and should replace the goed capstan :(
But I don't have the right rubber tubing ...



Hi Olivier,

If you're looking for someone near Paris, you should try this forum:


Printing "could" be old paper. Have you tried different paper to see if that helps?

There is a contact within the card reader that determines if the card is clipped or not. Perhaps it needs cleaning. If it does not make contact, logic assumes it is clipped.


I have tried different paper and I have also tried the same paper on my HP-41CX printer and printing was great. I am pretty sure the paper is not the issue.


Have a look at this thread regarding troubleshooting the write protect system and this one on how to bypass the write protect entirely.



I have by passed the two pins on the logic and it seems to have worked. What happens if one of the nylon balls in the card reader is missing?




If the ball is missing, that switch won't work.

I have found replacement polished Delrin balls at (1/8 inch diameter, part BDLR02 works).

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