Casio CFX-9800G Troubleshooting guide

R
CFX-9800G(LX-392AA)
MAR. 1995
(without price)
INDEX

CONTENTS
1. SCHEMATIC DIAGRAM
1-1. Main PCB ................................................................................................. 1
1-2. Power Supply and Key Block ................................................................ 2
2. SPECIFICATIONS .......................................................................................... 3
3. GENERAL GUIDE ........................................................................................... 4
3-1. Modes....................................................................................................... 4
3-2. About Display Colors ............................................................................. 5
3-3. Color Contrast Adjustment .................................................................... 5
3-4. About Low Battery Warning................................................................... 6
4. REPLACING BATTERIES............................................................................... 6
4-1. To Replace the Main Power Supply Batteries ...................................... 7
4-2. To Replace the Memory Back Up Battery............................................. 8
5. RESET OPERATION....................................................................................... 8
6. WELDING CONDITION FOR THE CERAMIC OSCILLATOR
(CSTC4.30MG-TC) ................................................ 10
7. ERROR MESSAGE ....................................................................................... 10
8. OPERATION CHECK .................................................................................... 12
9. COLOR ADJUSTMENT ON OPERATION CHECK ...................................... 14
10. DATA TRANSFER CHECK........................................................................... 16
11. DATA COMMUNICATIONS .......................................................................... 17
11-1. Connecting Two CFX-9800G Units.................................................... 17
11-2. Before Starting Data Communications ............................................. 17
11-3. Setting Communications Parameters ............................................... 18
11-4. Using ALL, Range, and Factor........................................................... 19
11-5. Data Communications Precautions .................................................. 20
12. PIN FUNCTION
12-1. CPU (HD62119A02) ............................................................................. 21
12-2. ROM (MB834000CPF-G-4EP) ............................................................. 22
12-3. RAM (256RAM/3V)............................................................................... 22
13. TROUBLESHOOTING................................................................................... 23
14. DISASSEMBLY AND EXPLODED VIEW ..................................................... 24
15. PARTS LIST ................................................................................................. .28

— 1 —
1. SCHEMATIC DIAGRAM
1-1. Main PCB
NOTES
1. The terminals with mark are the checking
points for the power supply.
2. The terminals with mark are the checking
points for the function.
3. LSI5 and C14 are not used.

— 2 —
1-2. Power Supply and Key Block

— 3 —
Current Consumption
TYP [µA] MAX [µA]
ON (MENU) 4610 5530
OFF 15
2. SPECIFICATIONS
Display system: Three colors (orange, blue, green); 16-character ×8-line liquid crystal
display;10-digit mantissaand 2-digitexponentforcalculations;displays
binary, octal, hexadecimal, sexagesimal values, fraction, complex
number
Power supply: Main: Two AAA-size batteries (LR03 (AM4) or R03 (UM-4))
Memory protection: One CR2032 lithium battery
Power consumption: 0.1W
Battery life*: Main: Approximately 120 hours (continuous display of initial screen.) with
battery type LR03 (AM4)
Approximately 80 hours (continuous display of initial screen.) with
battery type R03 (UM-4)
Approximately 2 years (power switch off) with LR03 (AM4)/R03
(UM-4)
Memory protection: Approximately 2 years
* The batteries that have been installed in this unit when user purchased
it had been used in the factory test, so it will be impossible to fully satisfy
this specifications when these batteries are used.
Auto power off: Power is automatically switched off approximately six minutes after last
operation except when drawing dynamic graphs.
Ambient temperature range: 0°C ~ 40°C (32°F ~ 104°F)
Dimensions: 17.4mm H ×95.5mm W ×182.5mm D (5/8" H ×33/4" W ×71/8" D)
Weight: 200g (7.1 oz) including batteries
Accessories: Hard case

— 4 —
3. GENERAL GUIDE
3-1. Modes
You can control the operations of the unit by entering the correct mode. To select the mode you
need, select the appropriate icon from the Main Menu. The Main Menu appears whenever you
press the
MENU
key.
The icon that is highlighted is the one that is currently selected. Use the cursor keys to move the
highlighting around the display to select the mode that you want. To enter the highlighted mode,
press the
EXE
key.
• In addition to using the cursor keys to select a mode's icon, you can also select a mode by input-
ting a number or letter. Input the number or letter in the lower right corner of the icon to select the
mode you want.
• Use only the procedures described above to enter a mode. If you use any other procedure, you
may end up in a mode that is different than the one you thought you selected.
The following explains the meaning of each icon in the Main Menu.
COMP Mode
Use this mode for arithmetic calculations and function calculations, for drawing graphs
and for executing programs.
BASE Mode
Use this mode for binary, octal, decimal, and hexadecimal calculations and conver-
sions. This mode is also used for logical operations.
SD Mode
Use this mode for single-variable statistical calculations (standard deviation), and for
drawing normal distribution and single-variable statistical graphs.
REG Mode
Use this mode for paired-variable statistical calculations (regression), and for drawing
paired-variable statistical graphs.
MAT Mode
Use this mode for matrix calculations.
GRAPH Mode
Use this mode to input functions and draw their graphs.
DYNA Mode
Use this mode to store graph functions and to draw graphs by changing the values for
variables in the functions.

— 5 —
TABLE Mode
Use this mode to store a function or recursion formula, to generate a solution table of
values produced when the values of variables in a function or recursion formula
change, and to draw graphs.
EQUA Mode
Use this mode to solve linear equations with two through six unknowns, quadratic
equations, and cubic equations.
PRGM Mode
Use this mode to store programs in the program area, to execute programs, and to
store and execute programs as file data.
LINK Mode
Use this mode to transfer program, function, matrix, and other memory data to another
unit.
OPTION Mode
Use this mode to adjust the color contrast of the display and to reset the calculator to
its initial settings.
3-2. About Display Colors
The calculator can display data in three colors: orange, blue, and green. The default color for graph
drawing and comment text accompanying a graph or program execution operation is blue, but you
can use the following procedure to change the color to orange or green if you want.
1. Display the Graph Color Menu.
SHIFT COLOR
F1 (Orn)..Orange graph and comment text
F2 (Grn)..Green graph and comment text
2. Press the function key that correspond to the color you want to specify for graph drawing and
comment text, and then input the text.
3. Execute the function or run the program to display the graph and comment text in the color you
specify.
3-3. Color Contrast Adjustment
Highlight the OPTION icon on the Main menu and then press
EXE
.
OPTION
TO SELECT: [ ↓][ ↑ ]
TO SET : [EXE]
COLOR CONTRAST
RESET
Orn Grn
F1 F2

— 6 —
✽✽ Low battery! ✽✽
3-4. About Low Battery Warning
If the following message appears on the display, immediately stop using the calculator and replace
batteries.
If you try to continue using the calculator, it will automatically switch power off, in order to protect
memory contents. You will not be able to switch power back on until you replace batteries.
Be sure to replace batteries at least once every two years, no matter how much you use the calcu-
lator during that time.
EXE
F1 (INIT). Returns tint to default setting.
F2 (IN·A). Returns tint and contrast to default setting.
• To adjust the contrast
1. Use and to move the pointer to CONTRAST.
2. Use to make the figures on the display darker or to make them lighter.
3. Press
MENU
to return to the Main Menu.
• To adjust the tint
1. Use and to move the pointer to the color you want to adjust (ORANGE, BLUE,
GREEN).
2. Use to move the setting toward the G (green) side or to move it to the O (orange) side.
3. Press
MENU
to return to the Main Menu.
• When adjusting the color contrast, first adjust overall display contrast, and then adjust the tint of
each individual color.
• You can also adjust the overall contrast whenever any other screen is shown on the display by
pressing
SHIFT
and then or . Press
SHIFT
again to exit the contrast adjustment procedure.
4.REPLACING BATTERIES
Warning!
If you remove both the main power supply and the memory back up batteries at the same time, all
memory contents will be erased.
COLOR
,,,
,,,
O B G
ORANGE
BLUE
GREEN
CONTRAST
INIT IN·A
– +
F1 F2

— 7 —
4-1. To Replace the Main Power Supply Batteries
* Never remove the main power supply and the memory back up batteries from the unit at the same
time.
* Be sure to switch the unit off before replacing batteries. Replacing batteries with power on will
cause data in memory to be deleted.
* Never replace the main power supply battery compartment cover or switch the calculator on while
the main power supply batteries are removed from the calculator or not loaded correctly. Doing so
can cause memory data to be deleted and malfunction of the calculator. If mishandling of batter-
ies causes such problems, correctly load batteries and then perform the RESET operation to
resume normal operation.
* Be sure to replace all two batteries with new ones.
1Switch the power of the calculator off, and slide the calcula-
tor into its hard case.
2Remove screw Aon the back of the calculator, and remove
the main battery compartment cover.
3Remove the two old batteries.
4Load a new set of two batteries, making sure that their
positive +and negative -ends are facing in the proper
directions.
5Insert the tabs of the main battery compartment cover into
the slots in the back of the calculator and replace the cover.
Secure it in place with the screw.
• Power will not switch on if you press
AC/
ON
while the main
power supply battery compartment cover is open.
6Remove the calculator from its hard case and press
AC/
ON
to
switch power on.
• Power supplied by memory back-up batteries while the
main power supply batteries are removed retains memory
contents.
• Do not leave the unit without main power supply batteries
loaded for long periods. Doing so can cause deletion of data
stored in memory.
Precautions:
Incorrectly using batteries can cause them to burst or leak, possibly damaging the interior of the
unit. Note the following precautions:
• Be sure that the positive +and negative -poles of each battery are facing in the proper direc-
tions.
• Never mix batteries of different types.
• Never mix old batteries and new ones.
• Never leave dead batteries in the battery compartment.
• Remove the batteries if you do not plan to use the unit for long periods.
• Never try to recharge the batteries supplied with the unit.
• Do not expose batteries to direct heat, let them become shorted, or try to take them apart.
Screw A

— 8 —
4-2. To Replace the Memory Back Up Battery
* Before replacing the memory backup battery, switch on the unit and check to see if the "Low
battery!" message appears on the display. If it does, replace the main power supply batteries
before replacing the back up power supply battery.
* Never remove the main power supply and the memory back up batteries from the unit at the same
time.
* Be sure to switch the unit off before replacing batteries. Replacing batteries with power on will
cause data in memory to be deleted.
* Be sure to replace the back up power supply battery at least once 2 years, regardless of how
much you use the unit during that time. Failure to do so can cause data in memory to be deleted.
1Switch the power of the calculator off.
2Remove screw Bon the back of the calculator, and remove
the back-up battery compartment cover.
3Remove the old battery.
4Wipe off the surfaces of a new battery with a soft, dry cloth.
Load it into the calculator so that its positive +side is
facing up.
5Insert the tabs of the back-up battery compartment cover
into the slots in the back of the calculator and replace the
cover. Secure it in place with the screw.
6Switch the power of the calculator on and check for proper
operation.
Screw B
5. RESET OPERATION
Warning!
The procedure described here clears all memory contents. Never perform this operation unless you
want to totally clear the memory of the calculator.
You should perform the RESET operation whenever you want to initialize the calculator. If you need
the data currently stored in memory, be sure to write it down somewhere before performing the
RESET operation.
• To reset the calculator
1Switch the power of the calculator on.
2Press
MENU
to display the Main Menu.
3Use the cursor keys to select the OPTION icon and
then press
EXE
. Or you can simply press
Inc
while
the Main Menu is displayed.
OPTION
TO SELECT: [ ↓][ ↑ ]
TO SET : [EXE]
COLOR CONTRAST
RESET