Appendix C: Service and Maintenance93
3. The motor roller is over the second track. Over a period of time. it may not read properly.

Improper Card Reader/writer Operation

If your calculator appears to be operating properly except for the reading or writing of program cards:
1. Make sure that the W/PRGMRUN switch is in the correct position for desired operation: RUN position for reading cards; W/PRGM for recording cards.
2. If the drive motor does not start when a card is inserted, make sure the battery pack is making proper contact and has ample charge. Remember that the battery charger alone does not deliver enough current to operate the drive motor. A charger must be used in conjunction with a partially charged battery in order to drive the card reader motor. if the battery has been completely discharged, plug in the charger and wait 5 minutes before attempting to operate the card reader/writer.
3. If the card drive mechanism functions correctly, but your HP-65 will still not read or write program cards, the trouble may be due to dirty record/playback heads. Use the headcleaning card once as directed. Then, test the calculator using the two diagnostic program cards furnished with it, following the instructions provided. If difficulty persists, your HP-65 should be taken or sent to an authorized Hewlett-Packard customer service facility.
4. Cards must move freely past the record/playback heads. Holding acard back or bumping a card after the card drive mechanism engages could cause a card to be misread.
Cards can be accidentally erased if subjected to extreme magnetic fields (magnetometers at airports are in the safe range).