HP HP-97 User Manual

CORVALLIS DIVISION
A cackars 97-101
SERVICE NOTE
Page 3 of 7
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E. Adjust the motor switch last and back it out approximately % turn
from the contact position. (NOTE: the adjustment of the head switch
can affect the location of the start bit. If the start bit on the
card was made by a premature closing of the head switch due to
the entire contact sheet bending, the location of the start bit will
be on the extreme edge of the card or in front of the card. These
situations should be detected by using Magna-See to observe the
start bit location.
The switches are now adjusted.
F. Erase a blank card with a magnet. * Switch the calculator to
Write Program Mode and record the blank card.
G. Dip the card in Magna-See.** Check that all four tracks are
recorded. If any of the tracks are missing, check the head
by trying to read a prerecorded card. Set the oscilloscope at
50 mV and 1 millisecond and check the head signals while reading
a card. The same type of signal should be found on all wires except
the center black ground wires. The problem can then be isolated
between the head and the sense amp. Replace the defective part and
continue the repair.
H. The card reader should now be electrically functional. Motor
current must be adjusted and the noise of the assembly must also
be adjusted to an acceptable minimum.
i. Noise is caused by:
a. Lack of lubrication.
(continued...)
For more information, contact the Service Engineering Manager, Corvallis Division—1000 N.E. Circle Bivd., Corvallis, Oregon 97330
Telephone (503) 757-2000 ¢ TWX # 510-596-0683
Printed in U.S.A.

HP HP-97 Specifications

General

Brand	HP
Model	HP-97
Category	Calculator
Language	English