LG FM776F User manual

COLOR MONITOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
CHASSIS NO. : CA-106
FACTORY MODEL : FM776F
MODEL: 776FM (FM776F-EA)
Website:http://biz.LGservice.com
E-mail:http://www.LGEservice.com/techsup.html
OSD SET
*( ) ID LABEL MODEL No.

1. PICTURE TUBE
Size : 17 inch (Flat Slot Mask)
DefIection Angle : 90°
Neck Diameter : 29.1 mm
Diagonal Inch : 16”
Stripe Pitch : 0.24 mm
Internal : Anti-Glare
Viewer Size : 325.4 x 244.1
Face Treatment : W-ARASC (Anti-Reflective and
Anti-Static Coating)
2. SIGNAL
2-1. Horizontal & Vertical Sync
1) Input Voltage Level: Low= ≤0.8V, High= ≥2.1V
2) Sync Polarity : Positive or Negative
2-2. Video Input Signal
1) Voltage Level : 0~0.7 Vp-p
a) Color 0, 0 : 0 Vp-p
b) Color 7, 0 : 0.467 Vp-p
c) Color 15, 0 : 0.7 Vp-p
2) Input Impedance : 75 Ω
3) Video Color : R, G, B Analog
4) Signal Format : Refer to the Timing Chart
2-3. Signal Connector
15 Pin D-Sub Connector
2-4. Scanning Frequency
Horizontal : 30~70 kHz
Vertical : 50~160 Hz
3. Audio AMP
Amp Output : 2W+2W rms
Frequency : 100Hz ~ 20kHz (-3dB)
T.H.D : Less than 1%
Input Voltage : 0.7 Vrms / 20 kΩ
S/N : More than 40 dB
4. Speaker
Speaker Impedance : 4Ω
Speaker Type : Dome, Bassreflex, Closed
Input : Max (5W), Normal (3W)
5. POWER SUPPLY
5-1. Power Range
AC 100~240V, 50/60Hz, 2.0A Max.
5-2. Power Consumption
6. DISPLAY AREA
6-1. Active Video Area :
• Max Image Size - 325.4 x 244.1mm (12.91" x 9.61")
• Preset Image Size - 310 x 230 mm (12.20" x 9.06")
6-2. Display Color : Full Colors
6-3. Display Resolution : 1280 Dots x 1024 Lines/60Hz
6-4. Video Bandwidth : 110 MHz
7. ENVIRONMENT
7-1. Operating Temperature: 0°C~40°C (32°F~104°F)
(Ambient)
7-2. Relative Humidity : 8%~80%
(Non-condensing)
7-3. Altitude : 5,000 m
8. DIMENSIONS (with TILT/SWIVEL)
Width : 460.0 mm (18.11")
Depth : 440.0 mm (17.32")
Height : 439.0 mm (17.28")
9. WEIGHT (with TILT/SWIVEL)
Net Weight : 21.0 kg (46.30 lbs)
Gross Weight : 24.0 kg (55.92 lbs)
CONTENTS
SPECIFICATIONS
- 2 -
SPECIFICATIONS ................................................... 2
SAFETY PRECAUTIONS ........................................ 3
TIMING CHART ....................................................... 4
OPERATING INSTRUCTIONS ................................ 5
CONTROL LOCATIONS ......................................... 7
WIRING DIAGRAM ................................................. 8
DISASSEMBLY ....................................................... 9
BLOCK DIAGRAM ................................................. 12
DESCRIPTION OF BLOCK DIAGRAM...................13
ADJUSTMENT ...................................................... 15
TROUBLESHOOTING GUIDE .............................. 17
EXPLODED VIEW.................................................. 26
REPLACEMENT PARTS LIST .............................. 28
PIN CONFIGURATION .......................................... 34
SCHEMATIC DIAGRAM......................................... 38
PRINTED CIRCUIT BOARD................................... 40
MODE
MAX
NORMAL (ON)
STAND-BY
SUSPEND
OFF
H/V SYNC
ON/ON
OFF/ON
ON/OFF
OFF/OFF
POWER CONSUMPTION
less than 115W
less than 74W
less than 15W
less than 15W
less than 8W
LED COLOR
GREEN
AMBER
AMBER

SAFETY PRECAUTIONS
- 3 -
SAFETY-RELATED COMPONENT WARNING!
There are special components used in this color monitor
which are important for safety. These parts are marked
on the schematic diagram and the replacement
parts list. It is essential that these critical parts should be
replaced with the manufacturer's specified parts to
prevent X-radiation, shock, fire, or other hazards. Do not
modify the original design without obtaining written
permission from LG or you will void the original parts and
labor guarantee.
CAUTION: No modification of any circuit should be
attempted.
Service work should be performed only after
you are thoroughly familiar with all of the
following safety checks and servicing
guidelines.
SAFETY CHECK
Care should be taken while servicing this color monitor
because of the high voltage used in the deflection circuits.
These voltages are exposed in such areas as the
associated flyback and yoke circuits.
FIRE & SHOCK HAZARD
An isolation transformer must be inserted between the
color monitor and AC power line before servicing the
chassis.
• In servicing, attention must be paid to the original lead
dress specially in the high voltage circuit. If a short
circuit is found, replace all parts which have been
overheated as a result of the short circuit.
• All the protective devices must be reinstalled per the
original design.
• Soldering must be inspected for the cold solder joints,
frayed leads, damaged insulation, solder splashes, or
the sharp points. Be sure to remove all foreign
materials.
IMPLOSION PROTECTION
All used display tubes are equipped with an integral
implosion protection system, but care should be taken to
avoid damage and scratching during installation. Use only
same type display tubes.
X-RADIATION
The only potential source of X-radiation is the picture tube.
However, when the high voltage circuitry is operating
properly there is no possibility of an X-radiation problem.
The basic precaution which must be exercised is keep the
high voltage at the factory recommended level; the normal
high voltage is about 26kV. The following steps describe
how to measure the high voltage and how to prevent X-
radiation.
Note : It is important to use an accurate high voltage
meter calibrated periodically.
• To measure the high voltage, use a high impedance
high voltage meter, connect (–) to chassis and (+) to
the CDT anode cap.
• Set the brightness control to maximum point at full
white pattern.
• Measure the high voltage. The high voltage meter
should be indicated at the factory recommended level.
• If the meter indication exceeds the maximum level,
immediate service is required to prevent the possibility
of premature component failure.
• To prevent X-radiation possibility, it is essential to use
the specified picture tube.
CAUTION:
Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.

TIMING CHART
- 4 -
VIDEO
SYNC
CE
DF
AB
MODE
Resolution
Recall
H
O
R
I
Z
O
N
T
A
L
V
E
R
T
I
C
A
L
kHz
µs
µs
µs
µs
µs
µs
Hz
ms
ms
ms
ms
ms
ms
MODE 2
+
46.88
21.33
16.16
5.17
0.32
1.62
3.23
+
75.01
13.331
12.798
0.533
0.021
0.064
0.448
800
x
600
75Hz
Yes
MODE 3
+
53.68
18.63
14.22
4.41
0.57
1.14
2.70
+
85.07
11.755
11.178
0.577
0.018
0.056
0.503
800
x
600
85Hz
Yes
MODE 4
+
68.677
14.561
10.836
3.725
0.508
1.016
2.201
+
85.00
11.764
11.182
0.582
0.014
0.044
0.524
1024
x
768
85Hz
Yes
MODE 5
—
31.47
31.78
25.42
6.36
0.64
3.81
1.91
+
70.08
14.269
12.712
1.557
0.414
0.063
1.080
640
x
400
70Hz
Yes
MODE 6
—
31.47
31.78
25.42
6.36
0.64
3.81
1.91
—
59.94
16.684
15.254
1.430
0.318
0.063
1.049
640
x
480
60Hz
Yes
MODE 7
+
37.88
26.40
20.00
6.40
1.00
3.20
2.20
+
60.32
16.579
15.840
0.739
0.026
0.106
0.607
800
x
600
60Hz
Yes
MODE 8
—
43.269
23.112
17.778
5.334
1.556
1.556
2.222
—
85.008
11.764
11.093
0.670
0.023
0.069
0.578
640
x
480
85Hz
Yes
MODE 9
+
60.02
16.66
13.00
3.66
0.20
1.22
2.24
+
75.03
13.328
12.795
0.533
0.017
0.050
0.466
1024
x
768
75Hz
Yes
MODE 10
+
63.98
15.63
11.85
3.78
0.44
1.04
2.30
+
60.02
16.661
16.005
0.656
0.015
0.047
0.594
1280
x
1024
60Hz
Yes
MARK
E
A
B
C
D
F
E
A
B
C
D
F
Sync Polarity
Frequency
Total Period
Video Active Time
Blanking Time
Front Porch
Sync Duration
Back Porch
Sync Polarity
Frequency
Total Period
Video Active Time
Blanking Time
Front Porch
Sync Duration
Back Porch
FACTORY PRESET MODE
* Mode 1~Mode 4: Basic Mode (Mode 5~Mode 10: Default Mode)
MODE 1
—
37.50
26.67
20.32
6.35
0.51
2.03
3.81
—
74.99
13.335
12.802
0.533
0.026
0.080
0.427
640
x
480
75Hz
Yes

OPERATING INSTRUCTIONS
- 5 -
REAR VIEWFRONT VIEW
Front Control Panel
See Front Control Panel
Left Side Jacks
MIC
OUT AUD
IN
Audio In
Mic Out
D-Sub Signal Cable
AC Power Socket
OSD SET
Sound Mute
Sound Menu Button
OSD Button
Built-in Microphone
Power ON/OFF ButtonSET Button
Power (DPMS) Indicator
1. Power ON/OFF Button
This button is used to turn the monitor ON and OFF.
2. Power Indicator
This Indicator lights up green when the monitor
operates normally. If the monitor is in DPM (Energy
Saving) mode (stand-by/suspend/power off), this
indicator color changes to orange.
3. SET Buttons
Use this button to enter a selection in the on screen
display.
4. OSD Select/Adjust Button
Use these buttons to choose or adjust items in the on
screen display.
5. OSD Button
Use this button to enter or exit the on screen display.
6. Built-in Microphone
Built-in Microphone.
7. Sound Mute
Used to select mute on (means sound off) and mute
off (means sound on).
8. Sound Menu
To adjust sound menu.

- 6 -
Headphone Jack Headphone Jack that automatically mutes the speaker volume when
headphone is attached.
Microphone Jack An external microphone can be used instead of the built-in
microphone.
Mic. Out Connects microphone sound to PC via cable.
Audio In Connects speaker sound to PC via cable attachment.
Microphone Operation
On the left side there is a MIC (Microphone) jack. By plugging a microphone in here, it may reduce the
long length of cable needed to reach the PC's sound card. In order to use this MIC jack, you need to use
a cable (supplied) to plug into the rear of the monitor (MIC OUT) and into the MIC input jack of your
sound card (if available).
Audio Features
A major feature of this monitor is its built-in audio system. This conveniently integrates a stereo audio
amplifier and speakers without taking up any more space. Because the monitor is designed like this, you
can easily upgrade to audio capable multimedia applications by attaching your PC with sound card to the
back of this monitor. It will result in significantly less cabling and space requirements.
Left Side Jacks
Rear Panel Jacks

CONTROL LOCATIONS
- 7 -
VR901: B
Adjustment
+

WIRING DIAGRAM
- 8 -
P201
P403
P904
P301
P302
P702
P805
P2
P1
P3P4
P902
MIC-OUT
Audio-IN
P704
P701
P703
P401
P804
P803
P802 P801
S+
S
G2
Signal
Cable
AC
Socket
FBT
P402
P502
P501(Purity Coil)
Speaker
Speaker

DISASSEMBLY
- 9 -
(b)
(b)
(a)
(a) (c)
3. SPEAKER ASS’Y REMOVAL
1) Remove four screws (a).
2) Disconnect P802 and P4.
3) Remove the Speaker Ass’y.
2. BACK COVER REMOVAL
1) Remove two screw covers (a).
2) Remove four screws (b) from the Back Cover.
3) Remove the Signal Cap (c).
4) Slide the Back Cover away from the Front
Cabinet of the monitor.
P802 (to P4)
(a)
(a) (a)
(a)
(a)
1. TILT/SWIVEL REMOVAL
1) Set the monitor face downward.
2) Pressing the latch (a), carefully remove
the Tilt/Swivel by pulling it upward.

- 10 -
P403
P402
P2
P3 P1
P302
P904
P702
P301
(a)
(b)
(b)
(a)
P704
P804P803
P802
P502
P501
P401
P201
P701
SET
P902
P801
(a)
(b)
(a)
(c)
(c)
4. TOTAL CHASSIS ASSEMBLY REMOVAL
1) Disconnect P902 (Degaussing pin),
P704 (DY pin), P502, P501 and P701
from the Main PCB.
2) Disconnect P401.
3) Disconnect eight connects (a).
4) Carefully separate the CDT Board
Assembly from the CDT neck.
5) Discharge the remaining static
electricity by shorting between
the Anode Cap and the CDT ground.
6) Disconnect the Anode Cap
from the CDT.
7) Disconnect P801, P802, P803, P804.
8) Remove the screw (b).
9) Remove the MIC Phone Assembly.
10) Remove two screws (c).
11) Remove the Total Chassis Assembly
from the Main Frame.
(a)
5. VIDEO PCB ASSEMBLY & AUDIO ASSEMBLY REMOVAL
1) Remove three screws (a).
2) Disconnect P1, P2, P3.
3) Remove the Audio Assembly.
4) Remove three screws (a).
5) Disconnect P301, P302, and Pin (b).
6) Remove the Video PCB Assembly.
(b)
(a)

- 11 -
(b)
(b) (a)
(b)
(b)
(b)
(b)
(b)
(b)

6. REAR JACK & INTERFACE ASSEMBLY REMOVAL
1) Remove the screw (a).
2) Remove the Rear Jack Assembly.
3) Remove eight screws (b).
4) Carefully remove the Interface Assembly
from the Main Total Ass’y.
(a) (a)
(a)
7. MAIN BRACKET REMOVAL
1) Remove three screws (a).
2) Remove the Rear Bracket.
3) Release five latches (b),
and remove the Bottom Bracket.
(b)
(b)

BLOCK DIAGRAM
- 12 -
Input Voltage
100~240VAC
(50/60Hz)
Line Filter
Degaussing Cir.
[ OSD Con trol ]
Power
Control
IC
(IC901)
TILT
Control
Cir.
6.3V
15V
E2PROM
(IC402)
5V
OSD IC (IC301)
H Sync. sig. V Sync. Sig. I2C DATA(SDA)
I2C CLOCK(SCL)
VIDEO
Pre Amp.
(IC302)
Input
Signal R
G
BVIDEO
Main Amp.
(IC303)
CUT OFF Circuit
(IC304)
80V
5V
Vertical Output
( IC601)
TDA4866J
H Defleciton
( Q706)
H-Linearity
Circuit.
Dynamic
Focus Cir.
- 120V
40V
15V
12V
MICOM
(IC401)
SCL / SDA
H/V Sync S ignal
PWM Control Signal 15V
15V
50V
DY CDT
Heater ( 6.3V )
I2C
I2C
I2C
H/V Sync
Signal
Screen
H.V
R/G/B
Bias
R/G/B
Contrast
H Drive
B-Drive
B+
15V
I2C
BRIGHTNESS/CONTRAST COLOR CURVE H / V POSITION H / V SIZE SPCC TRAPEZOID PIN BALANCE PARALLELOGRAM TILT TOP CORNER BOTTOM CORNER RECALL DEGAUSSING MOIRE LANGUAGE Audio Control -Volume -Treble -Bass -Balance -Microphone Audio Mute
850V
15V
6.3V
12V 80V
PURITY
Control
Cir. 15V
6.3V
Degaussing Coil
Dynomic Focus
Static Focus
TILT Coil
PURITY Coil
50V
80V
5V
G2 G1
Auto Beam
Limit Circuit
DC/DC Converter
FBT
( T701 )
Regulation
Circuit
15V
SMPS
(T901)
Vertical Blanking,
Brightness Contorl
Circuit
X-RAY
Protection
Circuit
H/V Sync. Processor
( IC701 )
TDA4841
D/D
Feed Back
Energy Savi
Sound (15V)
ng
Control Cir
Voltage Feedback REGULATOR
(Q1)
AUDIO IN
TO PC
l C
2
9V
MIC MIC OUT
AUDIO PRE-AMP
(IC1)
.
AUDIO MAIN-AMP
(IC2) SPEAKER

DESCRIPTION OF BLOCK DIAGRAM
- 13 -
1. SMPS(Switching Mode Power Supply)
When you turn on the power switch, the operating
procedure is as follows:
1) The AC line voltage is rectified by the bridge diodes
D900 and C908
2) The control IC(IC901) starts switching and generates
switching pulses in the primary turns of the SMPS
transformer (T901)
3) The switching pulses of the primary turns induce the
secondary pulse of the transformer by the turn ratio.
These pulses are rectified by each diode
(D971,D961,D962,D951,D942, D941 and D901)
4) Each rectified DC voltage (80V, 50V, 15V, 6.3V, 5V and
Audio(15V)) is supplied to the main circuit.
2. Over Voltage Protection Circuit
When the input voltage of IC901 Vin(pin 7) is more than
Spec Voltage , all the secondary voltages of the SMPS
transformer (T901) down to low value.
3. Display Power Management Circuit
1) Stand-by and Suspend mode.
When no input of horizontal or vertical sync, Q972&
Q952 are turned off.. then input power consumption is
below 15 watts
2) OFF mode
When no input of horizontal and vertical sync, Q942 is
turned off and all the secondary voltages of the SMPS
transformer (T901) down to low value. Then input power
consumption is below 3 watts
4. X-ray Protection Circuit
If the high voltage of the FBT reaches up to 29KV IN an
abnormal case, Q807 operates and IC401 pin 19 came to
low level, then IC401 control IC701 to stop Horizontal
drive pulse and stop Horizontal deflection.
5. Microprocessor Control Circuit.
1) Horizontal and Vertical sync signals are supplied to the
microprocessor (IC401).
2) Microprocessor(IC401) discriminates the operating
mode from the sync. polarity and resolution..
3) After microprocessor reads these adjusted mode data
stored at EEPROM, it controls operating mode data
through IIC.
4) Users can control screen condition by the OSD, SET,
UP, DOWN, RIGHT and LEFT buttons.
6. D/D (DC to DC) Convert Circuit.
To obtain constant high voltage, this circuit supplies
controlled DC voltage for FBT and Horizontal deflection
circuit according to the horizontal sync frequency.
7. Horizontal and Vertical Sync Processor Circuit.
The horizontal and vertical sync processor IC (IC701) has
a sync detector, a saw-tooth generator, and drive
function. So output horizontal and vertical drive signal
control screen distortions.
8. Horizontal linearity Circuit.
This circuit corrects the horizontal linearity for each
horizontal sync frequency.
9. Horizontal drive and Output Circuit.
This circuit is a horizontal deflection amplifier for raster
scan.
10. ABL Circuit.
This circuit limits the beam-current for the reliability of the
CDT.
11. Vertical Output Circuit.
This circuit takes the vertical ramp wave from the
TDA4841(IC701) and performs the vertical deflection by
supplying the saw-tooth wave current to the vertical
deflection yoke.
12. Blanking and Brightness Control Circuit.
Blanking circuit eliminates the retrace line by supplying a
negative pulse wave to the G1 of the CDT. Brightness
control circuit is used for control of the screen brightness
by changing the DC level of the G1.
13. Video Processor Circuit.
Video processor circuit consists of the video drive output
block. The video drive IC(IC302) receives the video
signal from PC. The gain of each channel is controlled by
the voltage of contrast pin. The cut-off circuit compensate
different voltage of each channel between thecathode
and the G1 of the CDT.
14. OSD (On-Screen-Display) Circuit.
This circuit displays on the screen information of the
monitor's status.
15, Dynamic Focus Output Circuit.
This circuit takes the horizontal and the vertical parabola
waves from the TDA4866(IC701) and amplifies it to
maintain constant focus on center and corners in the
screen.
16. Image Rotation (Tilt) Circuit.
This circuit corrects the tilt of the screen by supplying the
image rotation signal to the tilt coil which is attached near
the deflection yoke of the CRT
17. Earth Magnetic Correction(Purity) Circuit
This circuit corrects the convergence of screen by
supplying the convergence signal to the Coil which is
attached to the CRT near the deflection
18. Audio circuit
The sound circuit get to the audio gain with the pre-
amp(IC1) and the main amp(IC2).
The speaker maximum output is 3W.
If adjust to volume in OSD menu, the MICOM control to
IC1.

ADJUSTMENT
- 14 -
GENERAL INFORMATION
All adjustment are thoroughly checked and corrected
when the monitor leaves the factory, but sometimes
several adjustments may be required.
Adjustment should be following procedure and after
warming up for a minimum of 30 minutes.
•Alignment appliances and tools.
- IBM compatible PC.
- Programmable Signal Generator.
(eg. VG-819 made by Astrodesign Co.)
- EPROM or EEPROM with saved each mode data.
- Alignment Adaptor and Software.
- Digital Voltmeter.
- White Balance Meter.
- Luminance Meter.
- High-voltage Meter.
AUTOMATIC AND MANUAL DEGAUSSING
The degaussing coil is mounted around the CDT so that
automatic degaussing when turn on the monitor. But a
monitor is moved or faced in a different direction, become
poor color purity cause of CDT magnetized, then press
DEGAUSS on the OSD menu.
ADJUSTMENT PROCEDURE & METHOD
-Install the cable for adjustment such as Figure 1and run
the alignment program on the DOS for IBM compatible PC.
-Set external Brightness and Contrast volume to max position.
1. Adjustment for High-Voltage.
1) Set Brightness and Contrast to Max position.
2) Run alignment program for FM776F on the IBM
compatible PC.
3) EEPROM→ALL CLEAR→Y(YES) command.
<Caution> Do not run this procedure unless the
EEPROM is changed. All data in EEPROM
(mode data and color data)will be erased.
4) Display cross hatch pattern at Mode 4.
5) DIST. ADJ. →CTRL PWM command.
6) Adjust High Voltage to 25.8kV
± 0.1 kVdc.
2. Adjustment for Factory Mode (Preset Mode).
1) Display cross hatch pattern at Mode 1~4.
2) Run alignment program for FM776F on the IBM
compatible PC.
3) EEPROM→ALL CLEAR→Y(YES) command.
<Caution> Do not run this procedure unless the
EEPROM is changed. All data in EEPROM
(mode data and color data)will be erased.
4) COMMAND →START →Y(Yes) command.
5) DIST. ADJ. →CTRL PWM → TILT command.
6) Adjust tilt as arrow keys to be the best condition.
7) DIST. ADJ. →BALANCE command.
8) Adjust balance of Pin-Balance as arrow keys to
be the best condition.
9) Adjust parallelogram as arrow keys to be the best
condition.
10) DIST. ADJ. →FOS. ADJ command.
11) Adjust V-SIZE as arrow keys to 230 ± 2mm.
12) Adjust V-POSITION as arrow keys to center of the
screen.
13) Adjust H-SIZE as arrow keys to 310 ± 2mm.
14) Adjust H-POSITION as arrow keys to center of the
screen.
15) Adjust S-PCC (Side-Pincushion) as arrow keys to be
the best condition.
16) Adjust TRAPEZOID as arrow keys to be the best
condition.
17) Display from Mode 1 to Mode 4 and repeat above
from number
11) to 16) .
18) PRESET EXIT →Y (Yes) command.
3. Adjustment for White Balance and Luminance.
1) COMMAND →PRESET START command.
2) Press the DEGAUSS on the OSD menu for
demagnetization of the CDT.
3) COLOR ADJ. →LUMINANCE command of the
alignment program.
4) Set Brightness and Contrast to Max position.
5) Display color 0,0 pattern at Mode 4.
6) COLOR ADJ. →BIAS ADJ. command of the
alignment program.
7) Set Sub-Brightness to 120(78h) position. Check
whether green color or not at R-BIAS and B-BIAS to
min position and G-BIAS to 0.2
± 0.05FL to position.
If it’s not green color, the monitor must repair.
8) Adjust R-BIAS and G-BIAS command to x=0.283
±
0.02 and y=0.298 ± 0.02 on the White Balance Meter
with PC arrow keys.
9) Adjust SUB-Brightnesscommand to 0.3 ± 0.1FL of the
raster luminance.
10)
Display color 15,0 box pattern (70x70mm) at Mode 4.
11) COLOR ADJ. →DRIVE ADJ. command of the
alignment program.
12)
Set SUB-Contrast to105(69h) position.
13) Set G-DRIVE to 90(5Ah) (decimal) at DRIVE of the
alignment program.

- 15 -
Figure 1. Cable Connection
MIC
OUT AUD
IN
220
Monitor to be
adjusted
IBM
Compatible PC
PARALLEL PORT
Power inlet (required)
Power LED
ST Switch
Power Select Switch
(110V/220V)
Control Line
Not used
RS232C
PARALLEL
V-SYNC POWER
ST
VGS MONITOR
E
V-Sync On/Off Switch
(Switch must be ON.)
F
A
B
C
E
F
A
B
C
1510
5
569
1
1
1
14
13
25
6
5V
5V
5V
4.7K
4.7K
4.7K
74LS06
74LS06
OFF ON
OFF
ON
11
VIDEO
SIGNAL
GENERATOR
14)
Adjust B-DRIVE and G-DRIVE command to white
balance x=0.283
± 0.02 and y=0.298 ± 0.02 on the
White Balance Meter with PC arrow keys.
15)
Adjust SUB-CONTRAST command to 50 ± 1FL of the
color 15,0 box pattern (70x70mm) .
16) Display color 15,0 full white patten at Mode 4.
17) COLOR ADJ. →LUMINANCE →ABL command.
18)
Adjust ABL to 32 ± 1FL of the luminance.
19) Exit from the program.
4. Adjustment for Focus.
1) Display H character in full screen at Mode 4.
2) Adjust two Focus control on the FBT that focus
should be the best condition.

- 16 -
TROUBLESHOOTING GUIDE
NO POWER
(POWER INDICATOR OFF)
TROUBLE IN D900
TROUBLE IN FUSE
(F901)
TROUBLE IN
IC901
TROUBLE IN
D941, D942, D951,
D961, D962, D971
TROUBLE IN
D908, ZD902, Q903, Q972,
Q971, Q952, Q951, Q942, Q941
CHECK
FUSE OK?
(F901)
CHECK
C908 VOLTAGE?
(AC120V: 160VDC,
AC220V: 304VDC)
NO
YES
YES
YES
YES
NO
NO
NO
CHECK
IC901 PIN 6
WAVEFORM
(SQUARE WAVE
COMES OUT?)
CHECK
D941, D942, D951,
D961, D962, D971
VOLTAGE?
1. NO POWER

- 17 -
2. NO CHARACTER
NO CHARACTER
CHECK
IC302
PIN 9 (5V) ?
CHECK
IC302 PIN 5, 6, 7 ?
CHECK
IC302 PIN 18, 19, 20 ?
CHECK
IC303
PIN 1, 2, 3 ?
CHECK
IC303 PIN 4 (80V)
PIN 8 (12V) ?
TROUBLE IN
P302 5V LINE
TROUBLE IN
PC SIGNAL,
P301 SIGNAL CABLE
TROUBLE IN
IC302
TROUBLE IN
P302 12V LINE/
80V LINE
TROUBLE IN IC303
NO
YES
NO
NO
YES
YES
YES
YES
NO
NO
CHECK
R, G, B CATHODE
VOLTAGE?
TROUBLE IN
R341~R343,
R331~R333, L311~L313,
D307~D315
TROUBLE IN
IC304 / CRT SOCKET
YES
NO

- 18 -
NO VIDEO
(POWER INDICATOR ON)
CHECK
POWER INDICATOR
GREEN or ORANGE?
CHECK
D712 ANODE
(-160V)?
CHECK
G1VOLTAGE?
(-45 ~ -55V)
TROUBLE IN
D712
TROUBLE IN
Q704
DPM MODE
(NO H and/or V SYNC)
ORANGE
NO
GREEN
YES
NO
3. NO RASTER
CHECK
CDT HEAT
VOLTAGE? (6.3V)
TROUBLE IN
D941, Q942, Q941
YES
NO
TROUBLE IN
CDT
YES

- 19 -
4. NO HORIZONTAL DEFLECTION
NO H-DEFLECTION
(ONE VERTICAL LINE)
CHECK
Q706?
CHECK
B+ VOLTAGE
(49.5V)?
CHECK
T701(FBT) PIN 2
(31KHZ, 60V
69KHZ, 130V ?
CHECK
Q705 COLLECTOR
WAVEFORM?
TROUBLE IN
Q706
TROUBLE IN
50V LINE
TROUBLE IN
Q719, Q720, D710
TROUBLE IN
Q705
TROUBLE IN
T701, P701
NO
NO
YES
YES
YES
YES
NO
NO
0V T

- 20 -
5. TROUBLE IN H-LINEARITY
UNBALANCED OF H-LIN.
CHECK
IC401
PIN 1, 2, 3, 24 ?
CHECK
Q711~Q716?
CHECK
L703, Q710, D730?
TROUBLE IN
IC401 (MICOM)
TROUBLE IN
Q711~Q716
TROUBLE IN
L703, Q710, D730
TROUBLE IN
C722, C723, C726, C729
NO
NO
NO
YES
YES
YES Cs SIGNAL TABLE
HORIZONTAL
FREQUENCY(fH)
30K ~ 34K
34K ~ 40K
40K ~ 45K
45K ~ 48K
48K ~ 56K
56K ~ 66K
66K ~ 70K
Cs1
L
L
H
L
H
L
H
Cs3
L
L
L
H
H
H
H
Cs2
L
H
H
L
L
H
H