HP 82104A Owner's Handbook Manual page 53

Accessories, Maintenance and Service 51
Improper Card Reader Operation
If your HP-41C system appears to be operating properly except for the
reading or writing of magnetic cards, check the following:
1.
Make sure that the calculator is in the proper operating mode.
Read the specific procedure for reading or writing magnetic cards.
If the display shows LOW BAT when you insert a card, the
batteries do not have sufficient power to operate the card reader.
Remove the card and insert new size N alkaline batteries in the
HP-41C. Refer to Batteries in appendix B of the HP-41C Own-
er's Handbook and Programming Guide.
If the display repeatedly shows MALFUNCTION when you insert a
card, the card reader head may be dirty. Use the cleaning card as
directed. If the MALFUNCTION display still shows when you
insert a card, try another card. If the difficulty persists, your
HP 82104A Card Reader should be taken or sent to an authorized
Hewlett-Packard repair facility.
Cards must move freely past the card reader heads. Holding a card
back or bumping a card after the drive mechanism engages could
cause a card to be misread. Always insert the card firmly into the
card reader.
CAUTION
Cards can be accidentally erased if subjected to strong
magnetic fields. Magnetometers and X-ray equipment at
airports are in the safe range.
Check the condition of your magnetic cards. Dirty or deeply
scratched cards may not read properly.
The MALFUNCTION display may also show if you operate the card
reader outside the temperature specifications.
If you are unsure asto the source of the problems, you may wish to
take your HP-41C and the HP 82104A Card Readerto your nearest
authorized HP retail outlet prior to sending the unit in for service.
By temporarily exchanging card readers or calculators, you and
the dealer may be able to determine which device is not function-
ing properly. Only the device that has been determined to be
malfunctioning should be sent to HP for service. If you and the