HP HP-97 User Manual

HP-97 Component-Level Maintenance
4-32. Probable causes for problems listed above are:
Problem Item Caused By
d, f ROM 0O
a, b, e Cathode Driver. (See paragraph 4-33)
c, d, e, f LED Module.
d, g Anode Buffers:
(1) Segments a,b,c,or d missing - replace UA4.
(2) Segments e,f,g, or h missing - replace U3.
d, e Bad connection to cable W1
4-33, If a digit position does not light when -8.888888888-88 is keyed
into the display, refer to table 4-9 and press the key(s) indicated
following the unlit position. If the calculator display agrees with that
shown, the LED display is faulty; if not the cathode driver U1 is faulty.
Table 4-9. Missing Digit Troubleshooting
DIGIT POSITION KEY(S) DISPLAY
1 (mantissa sign) [2] 2.
2 (3] [0] [TAN] 0.58
3 [eX] 1.00
4 [2] [ENTER] [3] [y*] 8.00
5 (0] 0.
6 (4] [VX] 2.00
T (4] [1/x] 0.25
8 (4] y,
9 (2] [ENTER] [+] 4.00
10 [0] [cos] 1.00
11 [3] 3.
12 [1] 1.
13 (exponent sign) (2] [EEX] 2.
14 (2] [ENTER] [-] 0.00
15 [2] [ENTER] [X] 4.00
4-34, CATHODE DRIVER IC REPLACEMENT
4-35. After replacing cathode driver integrated circuit U1, a new
value for resistor R2 may have to be selected. Refer to table 4-10.
y-27

HP HP-97 Specifications

General

Brand	HP
Model	HP-97
Category	Calculator
Language	English