I am in the process of repairing the card reader in my HP-97. I have used the HP97 service manual from the MoHPC DVDs, but there is one piece of information which I have not been able to read in the PDF manual scan because the original print was really too small. Specifically, the leaf switches in the HP-97 card reader mechanism have to be adjusted with accuracy. In the Card Reader Troubleshooting flowchart (pages 4-26 to 4-28 of the manual), three boxes instruct the reader to turn the adjustment screws clockwise until the switches close, then turn the screws counterclockwise -- it must be 1/2 turn, 1/4 turn or some other fraction but the print is so small that the scanning has blurred it completely!
If anyone could have a look at the original manual and tell me what these fractions should be, I would really appreciate their time and effort. Because an HP calculator should never be left unrepaired!