LG Flatron F900P User manual

COLOR MONITOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MODEL: F900P (FB910G-UL)
CHASSIS NO. : CA-116
FACTORY MODEL: FB910G

1. PICTURE TUBE
Size : 19 inch (Flat Slot Mask)
DefIection Angle : 90°
Neck Diameter : 29.1 mm
Strip Pitch : 0.24 mm
Diagonal Size : 457.5 mm
View Size : 366.0 x 274.5 mm
Face Treatment : AR-ASC (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 : 30~111 kHz
Vertical : 50~160 Hz
3. POWER SUPPLY
3-1. Power Range
AC 100~120/200~240V, 50/60HZ, 2.5/1.2A
AC 200~240V, 50/60Hz, 1.2A (PFC version)
3-2. Power Consumption
4. DISPLAY AREA
4-1. Active Video Area :
• Max Image Size - 366.0 x 274.5mm (14.40" x 10.80")
• Preset Image Size - 350 x 262 mm (13.78" x 10.31")
4-2. Display Color : Full Colors
4-3. Display Resolution : 1600 Dots x 1200Lines/85Hz
4-4. Video Bandwidth : 235MHz
5. ENVIRONMENT
5-1. Operating Temperature: 0°C~40°C (32°F~103°F)
(Ambient)
5-2. Relative Humidity : 10%~90%
(Non-condensing)
5-3. Altitude : 10,000 ft
6. DIMENSIONS (with TILT/SWIVEL)
Width : 466.6 mm (18.37")
Depth : 472.5 mm (18.60")
Height : 474 mm (18.66")
7. WEIGHT (with TILT/SWIVEL)
Net Weight : 24.0 kg (51.82 lbs)
Gross Weight : 28 kg (61.74 lbs)
8. USB Specifications
USB Standard :
Rev. 1.0 complied self-powered hub
Downstream power supply : 500mA for each (MAX)
Communication speed : 12 Mbps (Full), 1.5 Mbps (Low)
USB port : 1 Upstream port
4 Downstream ports
CONTENTS
SPECIFICATIONS
- 2 -
SPECIFICATIONS ................................................... 2
SAFETY PRECAUTIONS ........................................ 3
TIMING CHART ....................................................... 4
OPERATING INSTRUCTIONS ................................ 5
CONTROL LOCATIONS ......................................... 8
WIRING DIAGRAM ................................................. 9
DISASSEMBLY ..................................................... 10
BLOCK DIAGRAM ................................................. 11
DESCRIPTION OF BLOCK DIAGRAM...................12
ADJUSTMENT ...................................................... 14
TROUBLESHOOTING GUIDE .............................. 16
EXPLODED VIEW.................................................. 24
REPLACEMENT PARTS LIST .............................. 26
PIN CONFIGURATION .......................................... 34
SCHEMATIC DIAGRAM......................................... 35
PRINTED CIRCUIT BOARD................................... 37
MODE
MAX
NORMAL
STAND-BY
SUSPEND
OFF
H/V SYNC
OFF/ON
ON/OFF
OFF/OFF
POWER CONSUMPTION (USB)
less than 135W (150W)
less than 103W (118W)
less than 8W (20W)
less than 8W (20W)
less than 1W (20W)
LED COLOR
GREEN
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 manufacturer 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 27kV. 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 D
A
EF
BC
kHz
µs
µs
µs
µs
µs
µs
Hz
ms
ms
ms
ms
ms
ms
MODE 1
–
43.269
23.112
17.778
5.334
1.556
1.556
2.222
–
85.008
11.763
11.093
0.670
0.023
0.069
0.578
640
X
480
85Hz
Yes
MODE 2
+
53.674
18.631
14.222
4.409
0.569
1.138
2.702
+
85.061
11.756
11.178
0.578
0.019
0.056
0.503
800
X
600
85Hz
Yes
MODE 3
+
68.677
14.561
10.836
3.725
0.508
1.016
2.201
+
84.997
11.765
11.183
0.582
0.015
0.044
0.523
1024
X
768
85Hz
Yes
MODE 4
+
91.146
10.971
8.127
2.844
0.406
1.016
1.422
+
85.024
11.762
11.235
0.527
0.011
0.033
0.483
1280
X
1024
85Hz
Yes
MODE 5
+
93.750
10.666
7.901
2.765
0.316
0.948
1.501
+
75.000
13.333
12.800
0.533
0.011
0.032
0.490
1600
X
1200
75Hz
Yes
MODE 6
+
106.250
9.412
6.972
2.441
0.297
0.837
1.325
+
85.000
11.765
11.294
0.470
0.009
0.028
0.433
1600
X
1200
85Hz
Yes
MODE 7
–
106.27
9.410
6.600
2.910
0.460
0.840
1.510
–
85.000
11.763
11.292
0.470
0.009
0.029
0.433
1600
X
1200
85Hz
No
MARK
A
B
C
D
E
F
A
B
C
D
E
F
MODE
FACTORY PRESET MODE
Resolution
Recall
H
O
R
I
Z
O
N
T
A
L
V
E
R
T
I
C
A
L
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
VESA
H-MAX
* Mode 7 is not factory preset mode, is used to adjust H-Size Max.

OPERATING INSTRUCTIONS
- 5 -
DSUB
COMP
HD
VD
RGB
REAR VIEWFRONT VIEW
Front Control Panel
See Front Control Panel Power Button
USB port
D-Sub Signal Connector
AC Power Socket
1. Power 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 stand-by,
suspend or DPMS off mode, this indicator color
changes to amber.
3. MENU (or OSD) Button
Use this button to enter or exit the on screen
display.
4. Button
Use these buttons to choose or adjust items in
the on screen display.
5. SELECT/INPUT Button
Use this button to enter a selection in the on
screen display or use this button to change BNC or
D-Sub.
100
100
12543
The Contrast and Brightness functions are also available in
the On Screen Display (OSD) menu.
Button
Button
Bring up Contrast adjustment
Bring up Brightness adjustment

Universal Serial Bus
- 6 -
USB connection (Option)
(1) Connect the upstream port of the monitor to the downstream port of the USB
compliant PC or another hub using the USB cable.
(2) Connect the USB compliant peripherals to the downstream ports the monitor.
*USB(Universal Serial Bus) is supported WINDOWS98 and Higher.
Making use of USB (Universal Serial Bus)*
USB(Universal Serial Bus) is an innovation in connecting your different desktop peripherals conveniently to your
computer. By using the USB, you will be able to connect your mouse, keyboard, printer, and other peripherals to
your monitor instead of having to connect them to your computer. This will give you greater flexibility in setting
up your system. USB allows you to connect chain up to 120 devices on a single USB port, and you can “hot”
plug (attach them while the computer is running) or unplug them while maintaining Plug and Plug auto detection
and configuration. This monitor has an integrated self-powered USB hub, allowing up to 4 other USB devices to
be attached it.
USB Downstream Ports
Connect the cables from USB compliant
peripherals-such as keyboard, mouse,
printer, scanner, etc.
USB Upstream Port
To USB downstream port
of the USB compliant PC
or another hub cable
USB Upstream connector USB Downstream connector

Using the BNC connectors with other types of video cards. Follow the example that fits your needs.
1. In case of using a composite sync on green video signal(Sync On Green):
Connect each R,G and B video signals to BNC receptacles on the back of the monitor.
2. In case of using an external composite sync signal:
Connect each R, G and B video signals and composite sync signal to the BNC receptacles on the rear
panel.
3. In case of using a separate horizontal and vertical sync signal:
Connect each R, G and B video signals and the horizontal and vertical sync signal to BNC receptacles on
rear panel.
*
R
G
B
COMP.
HD VD
- 7 -
R
G
B
COMP.
HD
*
R
G
B
Blue
Blue
Blue
Green
Green
Green
Gray
Black
Red
Red
Red
NOTE
This package does not include the BNC connectors but you can purchase them at your local computer stores.
This monitor does not support the DDC function, if you use the
5 BNC connectors with other types of video cards.
HD : Horizontal Drive
VD : Vertical Drive
COMP : Composite
* Varies according to model.
Using the BNC connector with other types of video cards
Gray
* Varies according to model.

CONTROL LOCATIONS
- 8 -
VR801
: High Voltage Adjustment (27kV)
VR991
: B Adjustment (195V Line)
+

WIRING DIAGRAM
- 9 -
Degauss
DY
Purity
P402 P702
P401
Anode Cap
DY Assembly
Screw
P201-
(Control PCB)
P501
P901
P101
P102
P701
P502

DISASSEMBLY
- 10 -
1. TILT/SWIVEL & BACK COVER REMOVAL
1) Set the monitor face downward.
2) Carefully remove the Tilt/Swivel by pulling it upward.
3) Remove two screws (a).
4) Release the latch (c). (See Figure. 1 and Tip Spec.)
5) Slide the Back Cover away from the Front Cabinet of the monitor.
Back Cover
Cabinet
(c)
Tip
C
B
A
Tip Spec.
A(Width) : 5.0~15.0mm
B(Depth) : 0.6~0.9mm
C(Height) : 12.0mm
(a)
(a)
Figure.1

BLOCK DIAGRAM
- 11 -
SIGNAL
INPUT
SUB
TRANS
(T903)
SUB
TRANS
Control
(IC902)
TOP243Y

DESCRIPTION OF BLOCK DIAGRAM
- 12 -
1. Line Filter & Associated Circuit.
This is used for suppressing noise of power input line
flowing into the monitor and/or some noise generated
in this monitor flowing out through the power input
line.That is to say, this circuit prevents interference
between the monitor and other electric appliances.
2. Degauss Circuit & Coil.
The degauss circuit consists of the degaussing coil,
the PTC (Positive Temperature Coefficient) thermistor
(TH901), and the relay (RL901). This circuit eliminates
abnormal color of the screen automatically by
degaussing the slot mask in the CDT when turn on the
power switch.
When you need to degauss while using the monitor,
select DEGAUSS on the OSD menu.
3. SMPS (Switching Mode Power Supply).
This circuit works with power of 100~240V or
200~240V (50/60Hz) specially for PFC version.
The operation procedure is as follows:
1) AC input voltage is rectified and smoothed by
the bridge diode (D901) and the capacitor (C908).
2) The rectified voltage (DC voltage) is applied to the
primary coil of the transformer (T901, T902).
3) The control IC (IC901) generates switching pulse
to turn on and off the primary coil of the
transformer (T901) repeatedly.
4) The control IC (IC902) generates switching pulse
to turn on and off the primary coil of the
transformer (T902) repeatedly.
5) Depending on the turn ratio of the transformer, the
secondary voltages appear at the secondary coil of
the transformer (T901).
6) These secondary voltages are rectified by each
diode (D951, D952, D971, D972, D973, D974,
D975, D976) and operate the other circuits.
(Deflection, Video Amplifier, etc.)
4. Display Power Management Circuit.
This circuit control power consumption of the monitor
by detecting H and V sync signal. There are stand-by
and suspend mode. When no horizontal or vertical
sync signal input, the circuit consists of Q951, Q952,
IC904, IC952 and IC401 control signal becomes
stand-by and suspend mode. It’s power consumption
is below 8W. When no horizontal and vertical sync
signal input, it’s power consumption is below 1W.
5. X-ray Protection.
This circuit detects the rectified DC voltage comes
from the FBT pin 4. If the high voltage of the FBT
reaches up to about 30kV (abnormal state), H.V
control (IC801) detects. It stops B+voltage supplied to
the FBT (T801), and high voltage is not be generated,
(In the normal state, the high voltage is about 27kV.)
6. Micom(Microprocessor) Circuit.
The operating procedure of Micom (Microprocessor)
and its associated circuit is as follows:
1) H and V sync signal is supplied from Signal Cable to the
Micom (IC401).
2) The Micom (IC401) distinguishes polarity and
frequency of Hand V sync.
3) The Micom controls each OSD function signals.
(H-size, H-position, V-size, etc.)
4) The controlled data of each mode is stored in IC402.
User can adjust screen condition by each OSD
function. The data of the adjust screen condition is
stored automatically.
7. Horizontal and Vertical Synchronous Processor.
This circuit generates the horizontal drive pulse and
the vertical drive pulse by taking sync-signal from
Signal Cable. This circuit consists of the TDA4841
(IC701) and the associated circuit.
8. Oscillating Circuit for D/D Converter.
This circuit generates the pulse wave which has the
horizontal period by taking the output of the
TDA4841(IC701).
9. D/D (DC to DC) Converter.
This circuit supplies DC voltage to the horizontal
deflection output circuit by decreasing DC 195V which
is the secondary voltage of the SMPS in accordance
with the input horizontal sync signal.
10. D/D Drive & Convert Circuit.
This circuit is used for supplying B+voltage to
horizontal deflection output transistor (Q763).
11. Horizontal Deflection Output Circuit.
This circuit makes the horizontal deflection by
supplying the saw-tooth current to the horizontal
deflection yoke.

- 13 -
12. High Voltage Output & FBT (Flyback Transformer).
The high voltage output circuit is used for generating
pulse wave to the primary coil of the FBT (Flyback
Transformer (T801)). A boosted voltage (about 27kV)
appears at the secondary of the FBT and it is supplied
to the anode of the CDT.
And there are another output voltages such as the
dynamic focus voltage.
13. H-Linearity Correction Circuit.
This circuit corrects the horizontal linearity for each
horizontal sync frequency.
14. Vertical Output Circuit.
This circuit takes the vertical wave from the
TDA4841(IC701) and performs the vertical deflection
by supplying the saw-tooth wave current from the
TDA8172 (IC601) to the vertical deflection yoke.
15. Dynamic Focus Output Circuit.
This circuit takes H and V parabola wave from the
TDA4841(IC701), and amplifies these waves to offer
to the FBT (T801).
16. H& V Blanking and Brightness Control.
This circuit eliminates the retrace line by supplying a
negative pulse to the G1 of the CDT.
17. 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 to the CDT near the deflection.
18. Static Convergence Control Circuit.
This circuit corrects the convergence of the screen by
supplying the convergence signal to the 4H (STC) coil
which is attached to the CDT near the deflection.
19. Moire Reduction Circuit
This circuit reduce interference between the periodical
display pattern and the CDT's slot (or dot).
The positions of every other one dot video signal
beams (red, green, and blue beam) are shifted finely,
thus reducing interference.
20. OSD Circuit.
This circuit is used for performing the OSD (On-
Screen- Display) function.
When a user selects the OSD Select/Adjustment
control, the adjustment status displays on the screen.
21. Video Pre-Amp Circuit.
This circuit amplifies the analog video signal from 0-
0.7V to 0-4V. This circuit is operated by taking the
clamp, R, G, B drives, and contrast signals from the
Micom (IC401).
22. Video Output Amp Circuit.
This circuit amplifies the video signal which comes
from the video pre-amp circuit and amplified video
signal is applied to the CDT cathode.

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
DEGAUSSING on the OSD menu.
ADJUSTMENT PROCEDURE & METHOD
-Install the cable for adjustment such as run the alignment
program on the DOS for IBM compatible PC.
-Set external Brightness and Contrast volume to max position.
1. Adjustment for B+ Voltage.
1) Display cross hatch pattern at Mode 6.
2) Adjust C983 (+) voltage to 195V ± 0.5V with VR991.
2. Adjustment for High-Voltage.
1) Display cross hatch pattern at Mode 6.
2) Adjust CDT Anode voltage to 27kV ± 500V with
VR801.
3. Adjustment for Horizontal Raster Center.
1) Display cross hatch pattern at Mode 6.
2) Adjust the Back Raster should be center of the
screen with SW771.
4. Adjustment for Factory Mode (Preset Mode).
1) Display cross hatch pattern at Mode 1~6.
2) Run alignment program for FB910G 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 7.
DIST. ADJ. → SIZE MAX command. Save H-Size
Max at bezel size exactly.
5) COMMAND → PRESET START → Y(Yes)
command.
6) Display cross hatch pattern at Mode 6.
7) DIST. ADJ. → FOS. ADJ command.
8) Adjust H-POSITION as arrow keys to center of the
screen.
9) Adjust H-SIZE as arrow keys to 350 ± 2mm.
10) Adjust V-POSITION as arrow keys to center of the
screen.
11) Adjust V-SIZE as arrow keys to 262 ± 1mm.
12)Adjust TRAPEZOID as arrow keys to be the best
condition.
13) DIST. ADJ. → BALANCE DATA command.
14) Adjust TILT as arrow keys to be the best condition.
15) Adjust balance of Pin-Balance as arrow keys to be
the best condition.
16) Adjust parallelogram as arrow keys to be the best
condition.
17) Save of the Mode.
18) Save of the System.
19) Display from Mode 6 to Mode 1 and repeat above
from number 6) to 18).
20) COMMAND → PRESET EXIT → Y (Yes) command.
5. Adjustment for White Balance and Luminance.
1) Set the White Balance Meter.
2) Press the DEGAUSSING on the OSD menu for
demagnetization of the CDT.
3) Display color 0,0 pattern at Mode 6.
4) COMMAND → PRESET START → Y(Yes)
command.
5) Set Bightness and Contrast to max position.
6) COLOR ADJ. → LUMINANCE command of the
alignment program.
7) COLOR ADJ. → BIAS ADJ. command of the
alignment program.
8) Check whether blue color or not at R-BIAS and G-
BIAS to min position, Sub-Brightness to 90 position,
B-BIAS to 68 position. If it's not blue color, the
monitor must repair.
9) Adjust Screen control on the FBT to 0.15 ± 0.02FL
of the raster luminance.
10)Adjust R-BIAS and G-BIAS command to x=0.283 ±
0.006 and y=0.298 ± 0.006 on the White Balance

- 15 -
11) Display color 15,0 box full white pattern at mode 6.
12)DRIVE ADJ command.
13)Set B-DRIVE to 97 at DRIVE of the alignment
program.
14)Adjust R-DRIVE and G-DRIVE command to white
balance x=0.283 ± 0.003 and y=0.298 ± 0.003 on
the White Balance Meter with PC arrow keys.
15) Display color 15,0 box pattern(70x70mm) at Mode 6.
16)Adjust SUB-CONTRAST command to 40±1FL of
the raster luminance.
17)Display color 15,0 full white pattern at Mode 6.
18)COLOR ADJ. → LUMINANCE → ABL command.
19) Adjust ABL to 30 ± 1FL of the luminance.
20) Exit from the program.
6. Adjustment for Focus.
1) Display H character in full screen at Mode 6.
2) Adjust two Focus control on the FBT that focus
should be the best condition.

- 16 -
TROUBLESHOOTING GUIDE
1. NO POWER-1
NO POWER (5V OFF)
(POWER INDICATOR OFF)
TROUBLE IN
BRIDGE DIODE
(D901)
TROUBLE IN
FUSE (F901)
TROUBLE IN
Q901, R908, R909,
D907
CHECK
FUSE OK?
(F901)
CHECK
D901
BRIDGE DIODE?
NO
YES
YES
NO
NO
CHECK
C908(+) VOLTAGE
145VDC at 110V input
310VDC at 220V input
TROUBLE IN
IC902, D912, ZD931,
D911, IC905, ZD932
TROUBLE IN D951
YES
NO
CHECK
IC902 PIN 1
5.8V ?
YES

- 17 -
2. NO POWER-2
NO POWER (5V ON)
(POWER INDICATOR ON)
TROUBLE IN IC901
TROUBLE IN
Q903, IC904
TROUBLE IN Q901
CHECK
IC901 PIN 7
18V ?
CHECK
IC901 PIN 6
WAVEFORM ?
NO
YES
YES
NO
NO
CHECK
Q901
DRAIN (T901 PIN 9)
WAVEFORM?
CHECK D971, D972, D973,
D974, D975, IC971
YES

- 18 -
3. NO CHARACTER
CHECK
IC302 PIN 5, 6, 7 ?
CHECK
IC302 PIN 18, 19, 20,
PIN 9 (5V) ?
CHECK
IC303 PIN 1, 3, 5
PIN10 (12V),
PIN 6 (80V) ?
TROUBLE IN
P102, P301, SIGNAL
CABLE, PC SIGNAL
TROUBLE IN
IC302, P302
TROUBLE IN
IC303
TROUBLE IN
CDT SOCKET
NO
YES
NO
NO
YES
YES
CHECK
R, G, B CATHODE
VOLTAGE?
TROUBLE IN
IC304
NO
YES
NO CHARACTER

- 19 -
4. NO RASTER
NO VIDEO
(POWER INDICATOR
GREEN or AMBER)
CHECK
POWER INDICATOR
GREEN or AMBER ?
CHECK
SCREEN CONTROL
KNOB OF FBT
CHECK
VOLTAGE AT
D974/D975 CATHODE (195V)
D976 CATHODE (80V)
IC971 OUT (12V)
IC952 CATHODE
(6.3V)?
CHECK
IC401 (MICOM) PIN 6
5V (HIGH), IC801 PIN 2
12V (HIGH)?
ROTATE SCREEN
CONTROL KNOB TO
CLOCKWISE or
COUNTER CLOCKWIES
TROUBLE IN
IC401 (MICOM),
IC801
TROUBLE IN
CDT SOCKET, BOARD
TROUBLE IN PRIMARY
CIRCUIT OF T901
TROUBLE IN
P401, P101, P702, P302
SIGNAL CABLE
AMBER
GREEN
OK
YES
NO
YES
NO

- 20 -
5. NO VERTICAL DEFLECTION
NO V-DEFLECTION
(ONE HORIZONTAL LINE)
CHECK
IC601 Pin 2
(15V) ?
CHECK
IC601 PIN 4
(-15V)?
TROUBLE IN
T901 15V LINE
TROUBLE IN
T901 -15V LINE
TROUBLE IN
IC601, V-CIRCUIT
NO
NO
YES
YES
CHECK
IC701 PIN 12
(SAWTOOTH WAVE)? TROUBLE IN
IC701
NO
YES