Casio SF-4400 Troubleshooting guide

JUN. 1994
R
(with price)
SF-4400(LX-594A)
SF-4600B(LX-594E/F)
SF-4400 SF-4600B

CONTENTS
1. SCHEMATIC DIAGRAM.................................................................................................... 1
1-1. MAIN PCB.................................................................................................................. 1
1-2. KEY MATRIX ............................................................................................................. 2
2. SPECIFICATIONS ............................................................................................................. 3
3. TO REPLACE THE BATTERIES....................................................................................... 5
4. DATA TRANSFER............................................................................................................. 6
5. OPERATION REFERENCE............................................................................................. 10
5-1. RESET OPERATION ............................................................................................... 10
5-2. TO ADJUST THE DISPLAY CONTRAST ............................................................... 11
5-3. TO CHECK THE MEMORY STATUS...................................................................... 11
5-4. THE SOUND MENU................................................................................................. 11
6. LSI, IC (Pin function) ...................................................................................................... 12
6-1. CPU.......................................................................................................................... 12
6-2. RAM:µPD43256G-101215LL (LSI2,LSI3) ............................................................... 13
6-3. VOLTAGE REGULATOR:S-81253SGUP (REG1) .................................................. 14
6-4. VOLTAGE DETECTOR:S-80752AN (DET1)........................................................... 14
7. TROUBLESHOOTING..................................................................................................... 15
8. HARD CHECK ................................................................................................................. 18
9. ASSEMBLY VIEW ........................................................................................................... 23
10. PARTS LIST .................................................................................................................... 25

— 1 —
1. SCHEMATIC DIAGRAM
1-1. MAIN PCB
NOTE: 1.LSI4, R3, R11 are not mounted.
2.R1, R2 are not used.

— 2 —
1-2. KEY MATRIX

— 3 —
2. SPECIFICATIONS
Data storage:
Storage and recall of telephone, memo, schedule, reminder data; calendar display; secret area; editing;
memory status display.
Clock:
World time; reminder alarm; schedule alarm; daily alarm; accuracy under normal temperatures: ±3
seconds average.
Calculation:
10-digit arithmetic calculations; arithmetic constants (+, –, x, ÷); independent memory; percentages;
square roots; 20-digit approximations; date calculations; other mixed calculations.
General:
Display element: 16-column x 4-line LCD
Memory capacity: SF-4400: 32 KB (28579 bytes)
SF-4600B: 64 KB (61347 bytes)
Main component: LSI
Power supply: 2 lithium batteries (CR2032)
Power consumption: 0.05W
Battery life:
Approximately 450 hours continuous operation in Telephone Directory
Approximately 380 hours repeating one minute of input and 10 minutes of display in Telephone
Directory
Approximately 12 months for memory backup
Auto power off: Approximately 6 minutes after last key operation
Operating temperature: 0°C ~ 40°C (32°F ~ 104°F)
Dimensions:
Unfolded: 10.6H x 141W x 159.5Dmm (3/8"H x 5 1/2"W x 6 1/4"D)
Folded: 12.4H x 141W x 82Dmm (1/2"H x 5 1/2"W x 3 1/4"D)
Weight: 98.2g (3.5 oz)
Current consumption:
Storage Capacity:
The 64K bytes memory capacity (32K bytes for SF-4400) includes a 61347 bytes user area (28579
bytes for SF-4400). The following shows examples of what this means for the storage of data in
each mode.
Telephone Directory:
Approximately 2920 (1360 for SF-4400), under the following conditions:
8-character name
10-character telephone number
Power switch TYP. [µA] MAX [µA]
OFF 5.15 10.0
ON 256 420

— 4 —
Approximately 1460 (680 for SF-4400), under the following conditions:
8-character name
10-character telephone number
20-character address
Memo:Approximately 2780 (1290 for SF-4400), 20-character memos.
Schedule Keeper:
Approximately 1910 (890 for SF-4400), under the following conditions:
1 item per day, 20 characters per item
30 days per month
Starting time specified, alarm time set
Approximately 2190 (1020 for SF-4400), under the following conditions:
1 item per day, 20 characters per item
30 days per month
Starting time specified, no alarm time
Reminder:
Approximately 3600 (1680 for SF-4400), under the following conditions:
10 characters per item
Alarm time set
Approximately 4080 (1900 for SF-4400), under the following conditions:
10 characters per item
No alarm time

— 5 —
Screw
RESET
3. TO REPLACE THE BATTERIES
1) Loosen the screw on the back of the SF-4400/4600B
that holds the battery compartment cover in place,
and remove the cover.
2) Loosen the screw that secures one of the two 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 two batteries. Never mix old batteries with new ones, and be sure to use
CR2032 lithium batteries only.
6) After you replace all two batteries, replace the battery compartment cover and secure it by tightening
its screw.
• Be careful that you do not over tighten the screw.

— 6 —
2) Turn on the power switch of each machine.
3) The slavemachine mustbeset thedate ofFeb. 3rd, 1901into thememory underthe calculator mode.
Operation: 1. Press
2. Select "CAL" mode or press 6.
3.
If you don't set the date, the "PASSWORD" isn't transferred to the slave machine.
4. DATA TRANSFER
SF-4400/SF-4600B can transfer customers data to other SF-4400/SF4600B 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.
SB-60/62 accessory cable
ON MENU
TIME TIME TIME M+
DATE DATE DATE R
123
M SUN
1901/ 2/ 3

— 7 —
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-4400/4600B 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. Select "TEL" mode or press 1under MENU screen.
2. Press FUNC twice to display the second function menu.
• You can perform the above operation while the initial screen of the Memo Mode, Schedule
Keeper, Calendar, or Reminder is displayed also.
3. Press 4 to select DATA COMM.
4. Press 3 to select SET UP.
✻✻ SET UP PAR. ✻✻✻
PARITY E O N
BIT LENGTH 78
BPS 4800 9600
3
CAPS
•Nis blinking.
*If the password isn't
registered in the SF unit,
display shows Xinstead
of "1".
FUNC FUNC 1* TO SECRET AREA
2 ALL DELETE
3 LABEL EDIT
4 DATA COMM
CAPS
4
1 SEND
2 RECEIVE
3 SET UP PAR.
CAPS

— 8 —
*If the password isn't
registered in the SF unit,
display shows X instead
of "1".
5. 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 Memo Mode, Schedule
Keeper, Calendar, or Reminder is displayed also.
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 Memo Mode, Schedule
Keeper, Calendar, or Reminder is displayed also.
1* TO SECRET AREA
2 ALL DELETE
3 LABEL EDIT
4 DATA COMM
SET
2
DATA
RECEIVE OK
TO STOP
PRESS (ESC)
CAPS
CAPS
FUNC FUNC
∇
∇
∇
*If the password isn't
registered in the SF unit,
display shows X instead
of "1".
FUNC FUNC 1* TO SECRET AREA
2 ALL DELETE
3 LABEL EDIT
4 DATA COMM
CAPS
4
1 SEND
2 RECEIVE
3 SET UP PAR.
CAPS

— 9 —
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 “TRANSMIT 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 -
SEND ALL DATA?
SET/ESC
4
1
3
1 SEND
2 RECEIVE
3 SET UP
DATA
SENDING
TO STOP
PRESS (ESC)
CAPS
CAPS
CAPS
CAPS
SET or ESC

— 10 —
5. OPERATION REFERENCE
5-1. RESET OPERATION
The following procedure erases all data stored in the memory of the SF Unit.
Perform the following operation only when you want to delete all data and initialize the settings
of the SF Unit.
Remember-you should always keep copies of important data by writing it down, by transferring
it to a personal computer or other SF Unit.
To reset the SF Unit's memory
1. Switch on power and press the RESET button with a thin, pointed object.
Warning!
The next step deletes all data stored in the SF Unit's memory. Make sure that you really want
to delete the data before you continue!
2. Press Y* to reset the memory and delete all data or Nto abort the reset
operation without deleting anything.
* Note that the letter key you press to indicate "yes" depends on the
system language, as noted below.
English: Y Spanish: S German: J
French: O Italian: S
Following the reset operation described above, the Home Time display appears and the SF
Unit setting are initialized as noted below.
Home Time: 12-hour format
JAN/1/1994
AM/12:00 00
Zone: London(LON)
World Time: New York(NYC)
Daily Alarm: 12:00 PM
Menu Mode: Telephone mode
Language: English
ALL DATA
CLEAR!
OK? Y/N
CAPS
RESET
RESET button

— 11 —
5-4. THE SOUND MENU
The sound menu lets you switch the key input tone and the various alarms of the SF Unit on
and off.
The on/off status of each SOUND menu items is indicated by a dot, and the dot that is flashing
on the menu is the one that is currently selected.
Use and to change the currently selected (flashing) item. Use and to switch the
currently selected item on and off.
Sound: Schedule alarm →ON
Reminder Alarm →ON
Daily alarm →OFF
Key →ON
Character input: CAPS
5-2. TO ADJUST THE DISPLAY CONTRAST
1 Enter the Telephone Directory Mode.
• You could enter any mode except the Calculator mode here.
2 Press SHIFT and confirm that the "S" indicator is on the display.
3 Press CONT.
4 Use the and keys to adjust the contrast.
5 After you are finished, press ESC to clear the contrast adjustment display.
5-3. TO CHECK THE MEMORY STATUS
Hold down SHIFT CAPA to display a screen that shows the current memory status. To clear the
memory status display, release CAPA. (SF-4400)
✻✻✻✻ CAPACITY ✻✻✻✻
3%
FREE 27678
USED 901
SCHED AL ●ON OFF
REMINDER ●ON OFF
DAILY AL ON ●OFF
KEY ●ON OFF
Dot indicates on/off status
Flashing dot indicates currently selected item
✻✻✻✻ CONTRAST ✻✻✻✻
▲
(LIGHTER)
(DARKER)
▼
CAPS
CAPS
CAPS
∇
∇
Remaining memory
capacity
Total number of characters stored in memory
∇
∇
∇
∇

— 12 —
Pin No. Signal I/O Function
1 ~ 5 C0 ~ 4 Out Common Signal for display
6 GND In GND /0[V]
7,8 BZ1,2 Out Buzzer terminal
9 VDD In Power supply/5.3[V]
10 CSRA1 Out Chip enable signal (Not used)
11 CSRA2 Out Chip enable signal for RAM
12 CSROM Out Chip enable signal (Not used)
13 WEB Out Write enable signal for RAM
14,15 RA15,16 Out Address bus (Not used)
16 ~ 30 A0 ~ 14 Out Address bus
31 ~ 38 IO0 ~ 7 I/O Data bus
39 ~ 54 KY0 ~ 15 I/O Key signal
55 SW In Battery switch (On: "L"/0[V] Off: "H"/6[V])
56 DEBUG - Test for manufacturer
57 ON Out Data communication enable
58 CRCKI In GND/0[V]
59 SOUTB Out Transmission data output
60 SIN In Transmission data input
61 VDD In Power supply/5.3[V]
62 TEST - Test for manufacturer
63 VTM - Not used
6. LSI, IC (Pin function)
6-1. CPU
No.1
“

— 13 —
Pin No. Signal I/O Function
64,65 OSC I/O I/O Clock terminal (DT-26S)
67,69~71 V1 ~ 4 Voltage for LCD driver
OFF: 0[V] ON: V1: 0.64(Light) ~ 1.29(Dark)[V]
V2: 1.29 ~ 2.56 [V]
V3: 3.99 ~ 2.71 [V]
V4: 4.64 ~ 3.99 [V]
68 NC - Not used
72 INTO In Low battery detection INTO<5.2[V]=> No power on
73 STNT - VDD/5.3[V]
74 VLCD In Power supply/5.3[V]
75 ~ 171 S0 ~ 95 Out Segment signal for display
172 ~ 199 C5 ~ 32 Out Common signal for display
168,200 NC - Not used
6-2. RAM: µPD43256G-101215LL (LSI2,LSI 3)
A0 ~ A14 : Address input signal
IO0 ~ IO7: Data signal (Input/Output)
WE : Write enable signal
CS : Chip select signal
OE : Output enable signal
CPU (WEB)
CPU (CSRA1 or 2)

— 14 —
VSS
VDD
VDD
VDD
–VDET +VDET
OUT
GND
VIN
VREF
RA
RB
1
23
RI
+
–
1
2
3
VDD
OUT
VSS
6-3. VOLTAGE REGULATOR: S-81253SGUP (REG1)
Output Voltage (Vout) : 5.3V ±5%
6-4. VOLTAGE DETECTOR: S-80752AN (DET1)
Detection Voltage(–VDET) : 5.2V ±2.5%
[5.07V (MIN) ~ 5.33V (MAX)]
Input voltage Output voltage
>5.2V 5V
<5.2V 0V
2
Vin
1
Vout 3
GND
1
GND 2 Vin 3 Vout

— 15 —
7. TROUBLESHOOTING
< 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?
Adjust contrast
Replace batteries
Check other function
Refer to <No/Erratic display>
Adjust contact and clean battery
spring
N
Y
Y
N
N
Y
Y
N
N
Is contrast adjustment OK?
Is power of batteries enough?
Y
Is 3-pin of S-81253 (REG1) 5.3 [V]?
N
N
Are capacitor C8, C9, C10, C11, C12,
C13 OK?
Y
Replace REGT1
1
Y
Replace C8, C9, C10, C11, C12,
C13

— 16 —
NReplace PCB
< No key input >
1
NReplace CPU (LSI1)
Y
Y
Is 13-Pin of CPU (LSI1) sending
the signal?
Y
NReplace DET1
NReplace CPU (LSI1)
DoesRAMmakepositivecontactwith
PCB?
Y
NResolder RAM (LSI2 or LSI3)
Does key make positive contact with PCB
Ass’y
Y
DoesCPUmakepositivecontactwithPCB? N
Replace CPU (LSI1)
Y
Resolder CPU (LSI1)
Is 11-Pin of CPU (LSI 1) sending the
signal?
Replace RAM (LSI2 or LSI3) or CPU (LSI1)
Is 1-Pin of S-80752AN (DET 1) 5[V]?

— 17 —
< No/Erratic display >
Is input 2-Pin of S-81253 (REG1) 6[V]?
Is output 3-Pin of S-81253 (REG1)
5.3[V]?
Y
Y
N
N
Check batteries
Replace REG1
N
N
Does CPU (LSI1) make positive con-
tact with PCB?
*CONTRAST: MAX
Resolder
Y
N
Resolder/Replace CPU, IC
Y
< High current consumption >
Y
Check PCB
Is there any short circuit? Y
N
Are the several capacitors OK? Replace capacitors
Are voltage of several capacitors enough?
V1: 1.3 [V]
V2: 2.5 [V]
V3: 2.7 [V]
V4: 3.9 [V]
*
Replace CPU (LSI1)
Check solder part of C1, C2, C3,
C4, C7 or replace.

— 18 —
8. HARD CHECK
No. OPERATION DISPLAY NOTE
Turn on while short the short pad
(KEY61).
No display
All dots display
Checker display
Reverse checker display
1
2
3
5
6
7
TEST 2 MEMORY
MENU 3 KEY
4 BUZZER
1 DISP 5 I/F
DISP 4 RVS.
1 WHITE 5 FRAME
2 BLACK 6 DOT 4
3 CHECK. 7 TIME
Main menu
Display check
1
1
4
2
3
4
SEARCH
SELF TEST PROG.
PRESS SEARCH
QUIT BY OFF
CASIO SEP. 1993
The short pad is
located behind the
tape I.