Casio SF-4300A Troubleshooting guide

JAN. 1993
R
(without price)
SF-4300A(LX-571AT)
SF-4600(LX-571ET/FT)
INDEX

CONTENTS
1. SCHEMATIC DIAGRAM.................................................................................................... 1
2. SPECIFICATIONS ............................................................................................................. 3
3. TO REPLACE THE BATTERIES....................................................................................... 4
4. DATA TRANSFER............................................................................................................. 5
5. BLOCK DIAGRAM ............................................................................................................ 9
6. LSI, IC (Pin Function) ..................................................................................................... 10
7. To FIX TAB ASS'Y ........................................................................................................... 13
8. TROUBLE SHOOTING.................................................................................................... 14
9. HARD CHECK ................................................................................................................. 17
10. DATA TRANSFER CHECK ............................................................................................. 22
11. PCB VIEW........................................................................................................................ 26
12. ASSEMBLY VIEW ........................................................................................................... 27
13. PARTS LIST .................................................................................................................... 29

— 1 —
1. SCHEMATIC DIAGRAM
1-1. MAIN PCB

— 2 —
1-2. KEY MATRIX

— 3—
2. SPECIFICATIONS
Data storage:
Storage and recall of telephone, memo, schedule, reminder data; calendar display; mark
protection; secret area; editing; memory status display
Clock:
World time; reminder alarm; schedule alarm; daily alarm; accuracy under normal tempera-
tures: ±3 seconds average
Calculation:
10-digit arithmetic calculations; arithmetic constants (+, –, ×, ÷); independent memory;
percentages; square roots; 20-digit approximations; date calculations; other mixed calcula-
tions
General:
Display element: 16-column ×4-line LCD
Memory capacity: 32 KB / SF-4300A, 64 KB / SF-4600
Main component: LSI
Power supply: 3 lithium batteries (CR2032)
Power consumption: 0.05W
Battery life: Approximately 200 hours continuous operation in Telephone Directory
approximately; 150 hours repeating one minute of input and 10 minutes
of display in Telephone Directory; approximately 12 months for memory
back up
Test condition: 20°C
Auto power off: Approximately 6 minutes after last key operation
Operating temperature: 0°C ~ 40°C (32°F ~ 104°F)
Dimensions:
Unfolded: 12.4H x141W x80.5Dmm (1/2"H x 5-5/8"W x3-1/8"D)
Folded: 8.9H x141W x157Dmm (3/8"H x 5-5/8"W x6-1/4"D)
Weight: 110g (3.9 oz)
Current consumption:
Power switch MIN. [µA] MAX [µA]
OFF 9.51
ON 529 606
ON 1,287 1,398
(Operating)

— 4—
3. TO REPLACE THE BATTERIES
1) Loosen the screw on the back of the SF-4300A /
SF-4600 that holds the battery compartment
cover in place, and remove the cover.
2) Loosen the screw that secures one of the three
battery holders in place and remove the battery
holder.
Caution
Be sure to remove only one battery at a time.
Otherwise, you will lose all data stored in memory.
3) Replace the old battery with a new one, making
sure that the positive (+) side of the new battery
is facing up (so you can see it).
4) Replace the battery holder and secure it by tightening its screw.
• Be sure careful that you do not over tighten the screw.
5) Repeat steps 2) through 4) for the other two batteries.
• Be sure to replace all three batteries. Never mix old batteries with new ones, and be sure
to use CR2032 lithium batteries only.
6) After you replace all three batteries, replace the battery compartment cover and secure it
by tightening its screw.
• Be careful that you do not over tighten the screw.
Screw

— 5—
ON CAL TIME TIME TIME M+
DATE DATE DATE R
2) Turn on the power switch of each machine.
3) The slave machine must be set the date of Feb. 3rd, 1901 into the memory under the
calculator mode.
Operation:
If you don't set the date, the "PASSWORD" isn't transferred to the slave machine.
123
4. DATA TRANSFER
SF-4300A / SF-4600 can transfer customers data to other SF-4300A / SF-4600 with memory
protection only when replacing the LCD or the outer case. How to transfer the data.
* Before connecting the cable (SB-60/62), be sure to reset the slave machine to clear all
data.
1) Turn off the power switch and connect the two units using the cable (SB-60/62) as shown
in the drawing.
M SUN
1901/ 2/ 3
SB-60/62 accessory cable

— 6—
Setting up for Data Communications
The following procedures describe what you should do to set up for data communications
between two SF Units or between an SF Unit and a personal computer. In addition to
hardware connections, it details how to set up the communications parameters and how to
set up the SF-4300A / SF-4600 to receive data. By following these instructions carefully,
you can be ensured of successful communications every time.
To connect two SF Units
1. Check to make sure that the power of the two SF Units is switched off.
2. Remove the covers from the connectors on the two SF Units.
3. Connect the two SF Units using the optional SB-60/62 cable. You can also connect
them using an SB-60/62 cable.
Important
Be sure to replace the connector covers on the SF Units when you are not performing data
communications.
4) Check the hardware parameters.
1 While an initial screen is displayed, press FUNC twice to display the second function
menu.
• You can perform the above operation while the initial screen of the Telephone
Directory, Memo Mode, Schedule Keeper, Calendar, Reminder is displayed.
2 Press 4 to select DATA COMM.
3 Press 3 to select SET UP.
FUNC FUNC
2 ALL DELETE
3 LABEL EDIT
4 DATA COMM
CAPS
1 SEND
2 RECEIVE
3 SET UP
4 FDD
CAPS
SET UP
PARITY E O N
BIT LENGTH 78
BPS 2400 4800
CAPS
3
4

— 7—
∇
∆
SET
2 ALL DELETE
3 LABEL EDIT
4 DATA COMM
CAPS
1 SEND
2 RECEIVE
3 SET UP
4 FDD
CAPS
RECEIVE OK
TO STOP
PRESS (ESC)
CAPS
DATA
2 ALL DELETE
3 LABEL EDIT
4 DATA COMM
CAPS
FUNC FUNC
2
4
FUNC FUNC
4 If the units have another condition, reset as above.
• To change the parameters
1. Use the ∆and — cursor keys to change the selected parameter on the display.
2. Use the and cursor keys to change the high-lighted setting of the currently
selected parameter.
3. Press SET to store them in memory.
5) Set up the slave machine
1 While an initial screen is displayed, press FUNC twice to display the second function
menu.
• You can perform the above operation while the initial screen of the Telephone
Directory, Memo Mode, Schedule Keeper, Calendar, Reminder is displayed.
2 Press 4 to select DATA COMM.
3 Press 2 to select RECEIVE.
6) Set up the customer’s machine.
1 While an initial screen is displayed, press FUNC twice to display the second function
menu.
• You can perform the above operation while the initial screen of the Telephone
Directory, Memo Mode, Schedule Keeper, Calendar, Reminder is displayed.

— 8—
2 Press 4 to select DATA COMM.
3 Press 1 to select SEND.
4 Press 3 to select ALL DATA.
5 Press SET to start the send operation or ESC to abort the operation without sending
anything.
• Data is send in the sequence: Telephone Directory, Memo Mode, Reminder Mode,
Schedule Keeper, Calendar.
• To abort the send operation at any time, press ESC.
• If an error occurs during the send operation, the message “SEND ERROR!” appears
on the display. Press ESC to clear the error message.
6 After the send operation is complete, the display returns to the initial screen of the mode
you were in when you started this procedure.
1 ONE ITEM
2 MODE DATA
3 ALL DATA- SEND -
CAPS
1 SEND
2 RECEIVE
3 SET UP
4 FDD
CAPS
SEND ALL DATA?
SET/ESC
CAPS
SENDING
TO STOP
PRESS (ESC)
CAPS
DATA
4
1
3
SET / ESC

— 9—
5. BLOCK DIAGRAM
NM360
LCD diriver
CPU
µPD3056G-007 RAM
µPD43257AGU
-10/12LL
RAM
µPD43257AGU
-10/12LL
KEYBOARD
Jack
LCD
Voltages
switching
circuit
VCC
S-81250
HG-RD
Contrast
V1~V5
VDD
Power Supply
Battery
(CR-2032 X 3)
XC61AN
6302PR
GND
ON OFF
KAC,
K1~K14
Tx
Rx
P0P1
SW, ISW
Data Bus
Address
Bus
VDD1
VDD2
LCD
SF-4300A LD-B8272AY
SF-4600 CD408-TS
TAB Ass'y
L571-1 Ass'y
CONTRASTV1 V2 V3 V4 V5
Max.(V) 1.5 3.0 5.5 7.0 8.5
Min.(V) 1.0 2.0 4.0 5.0 6.0

— 10 —
6. LSI, IC (Pin function)
6-1. CPU: µPD 3056G-007 (LSI 1)
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
µPD 3056G-007
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Pin No. Signal I/O Function
1 ~ 8 P0 ~ 7 I/O PORT P0: I/F output P1: I/F input
9 VSS I GND (0V)P6, P7: For buzzer
10 XI I Clock input
11 TSB Test Terminal
12 X0 O Clock output
13 VDD2 O Internal power supply terminal Power OFF: 0V ON: 5V
14 VDD1 I Power supply terminal (+5V)
15 FI I Internal clock terminal
16 FO O Internal clock terminal
17 SW I Main switch signa Power ON: 0V OFF: 5V
18 ISW I Sub switch signal Power ON: 0V OFF: 5V
19 ~ 21 CS1 ~ 3 O Enable signal for RAM
22 FE O Enable signal for ROM
23 WE O Write enable signal for RAM
24 CKO O Clock signal for LCD driver (NM360)
25 ~ 32 IO0 ~ 7 I/O Data bus
33 ~ 48 A0 ~ 15 O Address bus
49 ~ 63 KAC ~ K14 Key signal from keyboard
64 INT I Interrupt terminal

— 11 —
6-2. RAM: µPD43256G-101215LL (LSI 2)
A0 ~ A14 : Address input signal
IO0 ~ IO7: Data signal (Input/Output)
WE : Write enable signal
CS : Chip select signal
OE : Output enable signal
µPD3056G-007 (WE)
µPD3056G-007 (CS3)
6-4. LCD driver: NM 360

— 12 —
6-5. VOLTAGE REGULATOR: S-81250HG-RD (IC3, IC4)
Output Voltage (Vout) : 5V ±5%
[4.75V (MIN) ~ 5.25V (MAX)]
6-6. VOLTAGE DETECTOR: RH5VA60AA-T1 (IC5)
Detection Voltage(–VDET) : 6V ±2.5%
[5.85V (MIN) ~ 6.15V (MAX)]
Input voltage Output voltage
>6V 5V
<6V 0V
2
Vin
1
Vout 3
GND
1
GND 2 Vin 3 Vout

— 13 —
7. TO FIX TAB ASS'Y
When fixing a TAB ass'y part to the main PCB, it is necessary to paint "Neji lock" after soldering the
cable to the place of soldering part for the against of a shock.
1) Parts code of "Neji lock"
Code No. Name Specification Unit Price (FOB:JAPAN)
0001 9829 Neji lock 1402B YEN1,590.-
2) Location of the painting part
TAB Ass'y
Painting place

— 14 —
8. TROUBLE SHOOTING
<No power on>
Does display appear by pressing
Reset button?
Does it sound by key enter?
Do batteries make positive contact
with the battery springs?
DoesCSB1228JT(X1)outputclock
pulses?
Adjust contrast
Replace batteries
Check other function
Refer to <No/Erratic display>
Adjust contact and clean bat-
tery spring
Replace X1
Replace C11, C19, C12, C13
Is 2-pin of TC7SO2F (IC 1) 5[V]? Adjust/Replace slide switch
N
N
N
N
Y
Y
N
N
Y
Y
Y
N
N
Y
Y
Y
N
Y
Replace IC5
1
Is contrast adjustment OK?
Is power of batteries enough?
Are capacitor C11, C19, C12, C13 OK?
Is 1-pin of XC61AN6302PR (IC5)
5 [V]?

— 15 —
Is 17-Pin of µPD3056G -007(LSI 1)
0[V]? Replace IC1
N
Is 18-Pin of µPD3056G-007 (LSI 1)
0[V]? NReplace TC4S69F (IC2)
Y
Replace IC4
N
Y
Y
N
Y
Does key make positive contact with
L571-1 Ass’y
Y
Replace C12, C13
NClean/Adjust contact
<No key input>
Is 3-Pin of S-81250HG-RD (IC4) 5[V]?
Refer to <No/Erratic display>
1
Are capacitor C12, C13 OK?
Replace µPD 3056G-007 (LSI1)

— 16 —
<No/Erratic display>
Is input 2-Pin of S-81250 HG-RD
(IC3) 9[V]?
Is output 3-Pin of S-81250 HG-RD
(IC3) 5[V]?
Y
Y
N
N
Check Q1, Q2
Replace IC3
Arevoltageofseveralcapacitorsenough?
V1: 1.5 [V]
V2: 3.0 [V]
V3: 5.5 [V]
V4: 7.0 [V]
V5: 8.5 [V]
N
N
Does TAB ASS’Y make positive
contact with L571-1 ASS’Y?
*CONTRAST: MAX
Replace TAB ASS’Y
Resolder/Replace LSI1
Resolder
Y
Y
Resolder/Replace LSI, IC
N
<High current consumption>
*
Y
Check solder part of R4~R8 or
Replace C6, C7, C8, C9, C10
Check PCB
Is there any short circuit? Y
N
Are the several capacitors OK? Replace capacitors

— 17 —
9. HARD CHECK
3ON
41
51
62
73
TEST 2 MEMORY
MENU 3 KEY
4 BUZZER
1 DISP 5 EXT
00:00:00
Turn the slide (battery) switch on
while short the short pad (T16,
T37).
2Check if timer is
working.
1. Turntheslide(battery)switch
off.
2. Push the P-button.
1
No. OPERATION DISPLAY NOTE
No display
DISP 4 RVS.
1 WHITE 5 FRAME
2 BLACK 6 DOT 4
3 CHECK. 7 TIME
Display check
All dots display
Checker display

— 18 —
No. OPERATION DISPLAY NOTE
84
95
10 6
11 7
12 ON
13 3
14 2
Reverse checker display
FRAME
Dots appear at corners.
00:00:00 Check if timer is
working.
KEY 1 RANDOM
2 AUTO Key check
TEST 2 MEMORY
MENU 3 KEY
4 BUZZER
1 DISP 5 EXT
No display