Casio SF-A7 Troubleshooting guide

SF-A7(LX-553A)

DC-8000(LX-553B)

FEB. 1995

(with price)

SF-A7

CONTENTS

SPECIFICATIONS ............................................................................................................1

REPLACING THE BATTERIES ........................................................................................2

TO RESET THE UNIT'S MEMORY...................................................................................2

TO SAVE THE DATA........................................................................................................3

OPERATION CHECK .......................................................................................................4

LOW BATTERY TEST ......................................................................................................6

TROUBLESHOOTING ......................................................................................................6

SCHEMATIC DIAGRAM ...................................................................................................7

EXPLODED VIEW.............................................................................................................9

PARTS LIST....................................................................................................................10

— 1 —

SPECIFICATIONS

Main Modes: Telephone Directory, Memo, Schedule, Reminder, Home Time, World Time

and Calculator.

Data storage: Storage and recall of telephone, memo, schedule, reminder data; secret

area; editing; memory status display.

Clock: Worldtime; reminder alarm; daily alarm; hourly time signal; accuracy under

normal temperatures: ±3 seconds average

Calculation: 10-digit arithmetic calculations; arithemetic constants (+, –, ×, ÷); independ-

ent memory; percentages; square roots; 20-digit approximations; other

mixed calculations

General:

Display element: 16-column ×3-line LCD

Memory capacity: 32KB (32768 bytes)

Main component: LSI

Power supply: 2 lithium batteries (CR2032)

Power consumption: 0.02 W

Battery life*: Approximately 1 year (1 hour use per day); approximately 1,800 hours

repeating one minute of input and 10 minutes of display in Telephone

Directory.

* The batteries that come installed in this unit when you purchase it are for

factory test purposes, so they will probably not provide normal service life.

Auto power off: Approximately 6 minutes after last key operation

Operating temperature: 0°C ~ 40°C (32°F ~ 104°F)

Dimensions (HWD):

Unfolded: 9.3 x 130 x 159.7 mm (3/8x 5 1/8x 6 1/4inches)

Folded: 12.4 x 130 x 82 mm (1/2x 5 1/8x 3 1/4inches)

Weight: 95.6 g (3.4 oz)

— 2 —

REPLACING THE BATTERIES

1. Loosen the screw on the back of the unit that holds the battery

compartment cover in place, and remove the cover by sliding

it to the direction indicated by the arrow.

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 careful that you do not overtighten the screw.

5. Repeat Steps 2 through 4 for the other battery.

•Be sure to replace both batteries. Never mix old batteries

with new ones, and be sure to use CR2032 lithium batteries

only.

6. After you replace both batteries, replace the battery compart-

ment cover and secure it by tightening its screw.

•Be careful that you do not overtighten the screw.

TO RESET THE UNIT'S MEMORY

Warning!

The following procedure erases all data stored in the memory of the unit. Perform the following operation

only when you want to delete all data and initialize the settings of the unit.

Remember — you should always keep copies of important data by writing it down.

1. Switch on power and press the RESET button with a thin, pointed object.

Warning!

The next step deletes all data stored in the unit's memory. Make sure that you really want to delete the data

before you continue!

RESET button

— 3 —

TO SAVE THE DATA

The unit can transfer the data stored to another unit.

CAUTION: Before connecting wires, be sure to put the units in transmission and receiving mode.

Furthermore, after completing saving data, remove wires while showing OK or NG on display. If no, data

stored in customer's unit are corrupted.

To save the data, the following steps must be followed;

1. Remove the battery cover of both units.

2. Press RESET button of both units.

3. Short the pad TR of customer's unit. (Display shows "T".)

4. Short the pad TR twice of slave unit. (Display shows "R".)

5. Connect 4 terminals on PCB with wires as shown in the figure below.

Home Time: 12-hour format

JAN/1/1995

AM/12:00 00

Zone: Tokyo (TYO)

World Time: London (LON)

Daily Alarm: 12:00 AM

Sound: Reminder alarm →OFF

Daily alarm →OFF

Key input tone →OFF

Hourly time signal →OFF

2. Press EXE to reset the memory and delete all data or any other key to abort the reset operation without

deleting anything.

Following the reset operation described above, the Home Time display appears and the unit settings are

initialized as noted below.

CP10

CP11

CP13

CP2

CP10

CP11

CP12

CP2

CP12

TR CP2

CP11

CP13

CP10

Customers Slave

Enlarge Enlarge

RESET button RESET button

— 4 —

6. Press SET key of customer's unit. (No display)

7. Press SET key of slave unit. (No display) (Saving data is completed, the display shows OK.)

8. Remove 4 wires while showing OK on display.

9. If the display shows NG, execute the above operation from 2.

OPERATION CHECK

No.

OPERATION

RESET

EXE

(SEARCH) 3, 4 times

TEST pad

DISPLAY

RESET?

1TEL 2SCHD 3REM

4SEC 5TIME 6ALM

MEMO

8CAL

1TEL 2SCHD 3REM

4SEC 5TIME 6ALM

MEMO

8CAL

All dots

Vertical stripes.

NOTE

RESET

Contrast adjustment

Confirm display and high-pitched

buzzer sound.

Confirmdisplayand alarmsound.

Confirm display and low-pitched

buzzer sound.

Bottom View

Enlarge

RESET button

TEST pad

Batteries

— 5—

DISPLAY

No display

= OK =

ALPHA

= NG =

ALPHA

NAME?

ALPHA

ASDFGHJKLZXCVBNM

TEL 23456

FAX 7890!

ALPHA

_FGHJKLZXCVBNM

TEL 23456

FAX 7890!

ALPHA

◆CAPACITY◆0%

USED 0

FREE 32768

ALPHA

No display

RESET?

1TEL 2SCHD 3REM

4SEC 5TIME 6ALM

MEMO

8CAL

NO.

OPERATION

TEST pad

(Takes 5 min.)

ON 1

A S D F G H J K

L Z X C V B N M

EXE

2 3 4 5 6

EXE

7 8

9 0

SYMBOL

EXE EXE

(SEARCH)

EDIT DEL DEL INS SPACE

CLEAR A EXE CAPA

OFF

RESET

EXE

NOTE

USER MODE (TEL)

RESET

— 6 —

NO.

OPERATION

(SEARCH) , 3 times

DISPLAY

1TEL 2SCHD 3REM

4SEC 5TIME 6ALM

MEMO

8CAL

NOTE

LOW BATTERY TEST

NO.

OPERATION

OFF

NOTE

VDD is 5.07V or below.

DISPLAY

LOW BATTERY !

TROUBLESHOOTING

CAUSE

Battery shortage

Poor contact of battery terminals

Defective TAB-LSI

Poor contact SW1

Poor soldering of power supply circuit

Defective PCB unit

Defective TAB LSI

Defective heat seal

Defective LCD

Poor soldering of power supply circuit

SOLUTION

Replace batteries

Replace or polish them

Replace it

Resolder them

Replace it

Resolder it

SYMPTOM

No power

No display or wrong display

— 7 —

SCHEMATIC DIAGRAM

Main PCB (1/2)

— 8 —

Main PCB (2/2)

Other manuals for SF-A7

This manual suits for next models

Table of contents

Other Casio Calculator manuals

Popular Calculator manuals by other brands

HP 35s Instruction guide

LEXIBOOK

LEXIBOOK EL350 instruction manual

HP HP-97 Service manual

Citizen

Citizen SDC-414N instruction manual

Canon

Canon P26-DHIII instructions

Citizen

Citizen 520DPA instruction manual

Sharp

Sharp EL-9900 Operation manual

Sharp

Sharp WriteView EL-W506 operation instruction

HP HP-67 Owner's handbook

Royal

Royal CBC2000 instruction manual

Heathkit

Heathkit IC-2009 Assembly manual

Universal

Universal UNV-15907 owner's manual

Sharp

Sharp EL-9650 Operation guide

Sharp

Sharp EL2192RII - Printing Calculator Operation manual

Ativa

Ativa AT-30i owner's manual

HP StreamSmart 400 user guide

HP 20b Business Consultant manual

HP 9g user manual