Casio DC-7500A Troubleshooting guide

DC-7500A
JUL. 1994
R
(without price)
DC-7500A
INDEX

— 1 —
SPECIFICATIONS
Display: Liquid crystal display
Power supply: Two lithium batteries (CR2025) ......... Main and Back-up
Power consumption: 0.004 W
Battery life: Main battery: approximately 2 years (1hour use per day)
Back-up battery: approximately 1 year after the "LOW BATTERY"
message appears on the display
Auto power off: Approximately 6 minutes after last key operation
Ambient temperature range: 0°C ~ 40°C (32°F ~ 104°F)
Dimensions: 11.9 (H) ×119 (W) ×77.5 (D) mm ..... Folded
(1/2" (H) ×4 5/8" (W) ×3" (D))
8.3 (H) ×119 (W) ×151 (D) mm ........ Unfolded
(3/8" (H) ×4 5/8" (W) ×6" (D))
Weight: 84.2 g (3 oz) (including batteries)

— 2 —
TELEPHON
OPERATION CHECK
Note: Before you do this operation, save the data to another unit.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
No. MODE DISPLAYKEY NOTE
CLEAR
SCHEDULE
B
V
AC
CONVERSION
M
N
EDIT
HOME/WORLD
ASDFGHJKL¥$£ °
CONVERSION?
SCHEDULE? °
A
SCHEDULE? °
A
QWERTYUIOP_ °
A
Hold down it for about two
seconds.
HKG
EDIT1994-01-01 PM
11: XX XX
SAT
1994-01-01 AM
12: XX XX
TYO
EDIT1994-01-01 AM
12: XX XX
g
NAME?
A☎
0.
–
0.
+
0.
×
0.
÷
0.
QWER YT
UPOI
ASDF HG
JLK
ZCX ALPHA

— 3 —
h
15
16
17
18
19
20
21
22
23
24
25
26
27
No. MODE DISPLAYKEY NOTE
REMINDER ANNIVERSARY?
TYO
EDIT1994-01-01 AM
12: XX XX
–
ON NAME?
A☎
Confirm buzzer
PASS WORD?
A
–
SPACE –
HOME/WORLD
Three times ALARM12:00
SPACE
Four times KEYe? OFF
SET KEYe?ON
See the figure below
Back-up
battery cover
Main
battery cover
RESET button
RESET RESET?
NAME?
A☎
SET
CAPA U0
A
F 500 ☎
f
e

— 4 —
DATA TRANSFER
DC-7500A can transfer the stored data to another DC-7500A.
Note: Before connecting wires, be sure to reset the slave unit.
1. Remove the battery cover for back-up battery.
2. Connect 4 terminals on the PCB with wires as shown in the figure below.
Slave machineCustomer's machine
Operation Display Operation Display
RESET ?
R ?
T ?
END
1Press RESET button.
2Short the pad 'TR'.
3Press SET key.
5
1Press RESET button.
2Short the pad 'TR'.
3Press CAPA key.
4Press SET key.
5
RESET ?
R ?
END
If the display shows 'NG', execute the operation from 2.
It takes around 15 minutes to transfer the data in case of memory full.
VDD VDD
IO11 IO11
IO12 IO12
IO13 IO13
IO12
VDD
TR pad
IO11 IO13
Wiring
Reset button Reset button
Customer's Slave

— 5 —
B2+ IC1 IC2
IC3 C5 R3
R2
BZ2
D2
D1
BZ1
IC4 D3
R1 C3
C2
C1
XT
LSI
B1+
PCB VIEW
TROUBLESHOOTING
Before the following solutions will be done, save data if possible.
SYMPTOM SOLUTIONCAUSE
No power Battery shortage Replace batteries
ResolderPoor soldering of the power
supply circuit
No display at all or wrong display Defective heat seal Replace it
Defective LCD Replace it

— 6 —
SCHEMATIC DIAGRAM
76 52
51
25
1
102
77
27
26
28
S9
S4
S1
S2
S3
S4
IO23
IO22
S54
C1
C2
C3
C4
C5 C6
C7
C8
C9
C10
S60
S59 S58
RESET
ON TEL
BUS/PE
Transmit connector
C3
C1
XT
C2
R1
IC1
4
2
1
IC2 2
1
4
R2
R3
BZ
BT1
BT2 D1 D2
D3
IC4 1
2
3
C5
IN11
IN12
IN13
IN14
OFF
1
Q
C DST
CLR
CAPA
2
W
A
Z
NUM
ALPHA
3
E
MC
S
X
SECRET
4
R
MR
D
C
5
T
M- :
F
+
V
6
Y
M+ /
G
-
B
7
U
'
H
X
N÷
M
8
I
% ?
J
9
O
12/24
K
SPACE
0
P
AM/PM
L
=
SET
CONVE
-RSION
SCHE
-DULE
HOME
WORLD
EDIT
REMIN
-DER
AC
TR
O51 IO34 /AC VSS
S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13
IC3
C4
LCD CA411-TS
LSI JTMP0340-1902S(PI)
IC1, IC2 TC7S02F
IC3 TC7S04F
IC4 RH5VL27CA/S-8072AL-AG
R1 62K 1/8W ±2%
R2, R3 100 1/8W
C1 18PF / 50V
C2 15PF / 50V
C3, C5 0.1uF / 25V
C4 10uF / 4V
D1, D2 MA151K
D3 MA704
BT1, BT2 CR2025
XT 32.768KHz
BZ EFB-S55C41A8
+
LSI
IO12
IO13
IO14
IO21
IO22
IO23
IO24
IO31
IO32
IO33
IO34
IN11
IN12
IN13
IN14
S1
S2
S3
S4
S5
S6
S7
S8
S9
S10
IO0
O52
O51
/AC
XOUT
XIN
VSS
RIN
TS
/CE
BZ
VOUT
VDD
VLC
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
S60
S59
S58
S57
S56
S55
S54
S53
S52
S51
S50
S49
S48
S47
S46
S45
S44
S43
S42
S41
S40
S39
S38
S37
S36
S35
S11
S12
VDD
S13
S14
S15
S16
S17
S18
S19
S20
S21
S22
S23
S24
S25
S26
S27
S28
S29
S30
S31
S32
VDD
S33
S34
ROUT
LCD

PARTS LIST FOB Japan
N Item Code No. Parts Name Specification Q M N.R.Yen R
Unit Price
ELECTRICAL PARTS
N C1 6511 7510 Chip capacitor CP018F602A7 1 20 C
N C2 2803 7023 Chip capacitor CP015I602T6 1 20 C
C3 6511 7560 Chip capacitor CP001A432T8 1 20 C
N C4 6413 2810 Tantalum capacitor CX0100N5119 1 5 C
C5 6511 7560 Chip capacitor CP001A432T8 1 20 C
N D1 6510 4990 Diode BC1MA151K03 1 10 C
D2 6510 4990 Diode BC1MA151K03 1 10 C
N D3 2390 2282 Diode BC10MA704T1 1 10 C
IC1 2105 1827 IC TC7S02F-TE85R 1 10 B
IC2 2105 1827 IC TC7S02F-TE85R 1 10 B
IC3 2105 1561 IC TC7S04F-TE85R 1 10 B
N IC4 2105 2681 IC RH5VL27CA-T1 1 10 B
N R1 2775 1862 Chip resistor CC0623213G7 1 20 C
N R2 2775 1869 Chip resistor CC0012211T9 1 20 C
XT 6510 4550 Crystal BD0063P2509 1 5 C
N R3 2775 1869 Chip resistor CC0012211T9 1 20 C
MECHANICAL PARTS
N 1 6413 2720 LCD spacer EE0L9611003 1 10 B
2 3335 5208 LCD CA411-TS 1 1 B
N 3 6413 2790 Heat seal FX201P50217 1 1 B
N 4 6413 2740 Sponge cushion FH100028104 1 5 X
5 3122 2380 Buzzer EFB-S55C41A8 1 10 X
6 6510 4500 Buzzer tape HGFC0000501 1 20 X
N 7 6413 2660 Push Button FB30L961001 1 10 X
N 8 6413 2750 Rating label HGC00L96102 1 10 X
9 6510 5250 Screw MAB80004209 3 20 X
10 6408 5830 Rubber button LADB0140101 1 20 X
N 11 6413 2770 Hard case FC10L961007 1 1 X
N 12 6413 2780 Operation label HGFC0010400 1 10 X
N 13 6413 2670 Display plate EL5F0009100 1 1 X
N 14 6413 2700 Upper cabinet FAA0L961008 1 1 X
N 15 6413 2690 Rubber sheet LA0L9610001 1 5 X
N 16 4311 9350 PCB DAL96XXXA13 1 1 X
N 17 6413 2680 Overlay mylar EL4F0003100 1 20 X
18 6410 9810 Battery plate (+) EF01DB10107 2 10 X
N 19 6413 2800 Battery plate (-) EF02DB10118 2 20 X
20 6510 4440 Nut tape HGFC0001206 2 20 X
21 6512 1080 Nut MD100000602 2 20 X
N 22 6413 2710 Battery cover FAD0L961001 2 20 X
N 23 6413 2730 Lower cabinet FAB0L961004 1 5 X
24 6390 7330 Screw MAB20013201 1 20 X
25 6512 1020 Screw MAA80009301 2 20 X
Note: In case of defective LSI, replace the whole unit.
Both LSI and PCB assembly can not be supplied.
N A011 5278 DC-7500A-DW-F LX-096ATLF 1 1
Notes: N – New parts R – A : Essential
M – Minimum order/supply quantity B : Stock recommended
R – Rank C : Others
Q – Quantity used per unit X : No stock recommended
— 7 —

— 8 —
EXPLODED VIEW
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12
14
15
13
11
10
8
5
6
4
3
1
2
16
17
18 19
20
21
22
23
24 25
18
7

8-11-10, Nishi-Shinjuku
Shinjuku-ku, Tokyo 160, Japan
Telephone: [phone]