CTX EX951F User manual

SERVICE MANUAL
COLOR MONITOR
P993Z Series
EX951F
CTX
P/N : P993Z-3-00-A
Date : Jun-02-03
Version : A00

1
THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY REASONABLE EFFORT
HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE CANNOT GUARANTEE THE
ACCURACY OF THIS INFORMATION AFTER THE DATE OF PUBLICATION AND DISCLAIMS LIABILITY
FOR CHANGES, ERRORS OR OMISSIONS,
MANUFACTURE DATE : Jun. 2003

2
TABLE OF CONTENTS
PAGE
1. SPECIFICATIONS ..................................................................................................... 3-4
2. PRECAUTION AND NOTICES ................................................................................ 5
2-1 SAFETY PRECAUTIONS .............................................................................. 5
2-2 PRODUCT SAFETY NOTICE ....................................................................... 5
2-3 SERVICE NOTES ........................................................................................... 5
2-4 HIGH VOLTAGE WARNING ....................................................................... 6
3. OPERATING INSTRUCTIONS ................................................................................ 7
4. ADJUSTMENT .......................................................................................................... 8
4-1 ADJUSTMENT CONDITIONS AND PRECAUTIONS ............................... 8
4-2 MAIN ADJUSTMENTS ................................................................................. 8
4-3 ADJUSTMENT METHOD ............................................................................. 8-11
5. CIRCUIT DESCRIPTION .......................................................................................... 11-13
6. TROUBLE SHOOTING CHART .............................................................................. 14
6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS .............................. 14-15
6-2 ABNORMAL DISPLAY ................................................................................. 16
6-3 NO BLANKING ........................................................................................... 17
6-4 HOR. /OSC /DEF /HV CIRCUIT FAULT ...................................................... 17
6-5 ABNORMAL HORIZONTAL DEFLECTION .............................................. 18
6-6 ABNORMAL VERTICAL SCANNING ........................................................ 19
6-7 SIDE-PIN CUSHION DISTORTION ............................................................. 19
6-8 POOR FOCUS ................................................................................................. 20
6-9 NO SOUND (FOR AUDIO MODEL ONLY)..................................…........... 20
6-10 POWER SUPPLY TROUBLE SHOOTING CHART .................................... 21
7. MECHANICAL OF CABINET FRONT DIS-ASSEMBLY...................................... 22
8. PARTS LISTING ....................................................................................................... 23-41
9. IC BLOCK DIAGRAMS............................................................................................ 42-46
10. PCB LAYOUT ............................................................................................................ 47-48
11. SCHEMATIC DIAGRAM ......................................................................................... 49

3
1. SPECIFICATIONS FOR 9Klr SERIES COLOR MONITOR
1. CRT : 46CM(19") 90 Deflection, 29mm Neck, flat 0.25mm Dot Pitch, Non-Glare Screen
2. Viewable image Size: 45.7CM (18") diagonal
3. Display Color: Unlimited Colors
4. External Controls:
Power On/Off, OSD key, Function knob: Contrast, Brightness, H-Size, H-Center, V-Size, V-Center, ZOOM,
Pincushion, Trapezoid, Pin-Balance, Parallelogram, Rotation, Moire Reduce, Recall, Degaussing, Color
Temperature, Volume. (For 9KlrA Model)
5. Input Video Signal
Mode 1 Mode 2 Mode 3 Mode 4
RGB Analog RGB Analog RGB Analog RGB Analog
Horiz. Sync: TTL Level TTL Level TTL Level TTL Level
Negative Negative Negative Positive
Vert. Sync: TTL Level TTL Level TTL Level TTL Level
Positive Negative Negative Positive
Horizontal: 720 (H) 640 (H) 640 (H) 800 (H)
Vertical : 400 (V) 480 (V) 480(V) 600(V)
Fh (kHz): 31.327 31.469 43.269 53.750
Fv (Hz) : 69.616 59.9 85.008 84.997
Mode 5 Mode 6 Mode 7 Mode 8
RGB Analog RGB Analog RGB Analog RGB Analog
Horiz. Sync: TTL Level TTL Level TTL Level TTL Level
Positive Positive Positive Positive
Vert. Sync: TTL Level TTL Level TTL Level TTL Level
Positive Positive Positive Positive
Horizontal: 1024 (H) 1280 (H) 1280 (H) 1600 (H)
Vertical : 768 (V) 960 (V) 1024 (V) 1200 (V)
Fh (kHz): 68.677 85.935 91.148 93.75
Fv (Hz) : 84.997 85 85 75
6. Display Size
Horizontal: 346 mm
Vertical: 260 mm
7. Scanning Frequencies
Horizontal: 30KHz ~98KHz
Vertical: 50 Hz ~160 Hz
8. Factory Preset Timings: 8
User Timings: 20
9. Mis-convergence
Center: 0.3 mm Max.
Corner: 0.4 mm Max.
10. Video Dot Rate: 200 MHz

4
11. Power Source:
Switching Mode Power Supply
AC 100 ~240V, 50/60Hz Universal Type
12. Operating Temperature: 0°C to 40°C Ambient
13. Humidity : 10% to 85% Relative, Non-Condensing
14•Weight: 20.0 Kg (Net), 23.6Kg (Gross) for 9Klr
15 Dimensions Monitor:
Carton: 575(W) × 526(H) × 655(D) mm
Monitor: 446(W) × 436(H) ×455 (D) mm for 9Klr
16. External Connection :
15 Pin D-type Connector AC Power Cord
17. Speaker: (for 9KlrA only)
Rate power: 1.5W (per channel)
Impedance: 8Ω
18. Regulations: UL, CSA, FDA, FCC, TÜV/GS, CE, Energy Star, MPR-II
TCO

5
2. PRECAUTIONS AND NOTICES
2-1 SAFETY PRECAUTIONS
1. Observe all caution and safety related notes located inside the display cabinet.
2. Operation of the display with the cover removed, may cause a serious shock hazard from the display power
supply. Work on the display should not be attempted by anyone who is not thoroughly familiar with
precautions necessary when working on high voltage equipment.
3. Do not install, remove or handle the picture tube in any manner unless shatter-proof goggles are worn.
People who are not so equipped should be kept away while handling picture tube. Keep picture tube away
from the body while handling.
4. The picture tube is constructed to limit X-RAY radiation to 0.5 mR/HR. For continued protection, use the
designated replacement tube only, and adjust the voltages so that the designated maximum rating at the
anode will not be exceeded.
5. Symbol “ ” means safety relative parts. The use of substitute replacement parts which do not have the
same characteristics as specified in the parts list may create shock, fire or explode etc.
6. Symbol “★” means important relative parts. Before replacing any of these components please read the parts
list in this manual carefully to avoid creating higher anode voltage or x-ray. Especially for sealed controls,
such as VR902, VR702 and FBT screen VR etc, which were sealed by the manufacturer once their
optimum position has been set, please don’t dismantle them as your likes, otherwise you will break or
damage the component. If you need replace the parts with sealed control, please adjust the relative VR to
make sure the B+ voltage under 137.5Vdc at 1024*768@85Hz and well seal it with A+B glue or equivalent,
which you can not move away with one screw driver.
7. Before returning a serviced display to the customer, a thorough safety test must be performed to verify that
the display is safe to operate without danger or shock. Always perform an AC leakage current check on the
exposed metallic parts of the cabinet, such as screw heads.
Test method for current leakage is described as follow.
(a) Plug the AC line cord directly into rated AC outlet (do not use a line isolation transformer during this
check).
(b) Use an AC voltmeter having 5000 ohms per volt or with more sensitivity in the following manner:
Connect a 1500 ohms 10 Watt resistor, paralleled by a 0.15UF, AC type capacitor between a known
good earth ground (water pipe, conduit, etc.) and the exposed metallic parts simultaneously. Measure
the AC voltage across the combination of 1500 ohms resistor and 0.15UF capacitor.
(c) Reverse the AC plug at the AC outlet and repeat AC voltage measurements for each exposed metallic
part.
(d) Voltage measured must not exceed 0.5 volts RMS. This corresponds to 0.35 milliamp AC. Any value
exceeding this limit constitutes a potential shock hazard and must be corrected immediately.
2-2 PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in this chassis have special safety visual inspections and the protection
afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage,
wattage, etc. Before replacing any of these components read the parts list in this manual carefully. The use of
substitute replacement parts which do not have the same safety characteristics as specified in the parts list may
create shock, fire, X-RAY radiation or other hazards.
2-3 SERVICE NOTES
1. When replacing parts or circuit boards, clamp the lead wires around terminals before soldering.
2. When replacing a high wattage resistor (more than 1/2W of metal oxide film resistor) in circuit board, keep
the resistor about 10mm (1/2 in) away from circuit board.
3. Keep wires away from high voltage or high temperature components.
4. Keep wires in their original position so as to reduce interference.

6
2-4 HIGH VOLTAGE WARNING
Operation of monitor outside of cabinet or with back removed may cause a serious shock hazard. Work on this
model should only be performed by those who are thoroughly familiar with precautions necessary when working
on high voltage equipment.
Exercise care when servicing this chassis with power applied. Many B plus and high voltage terminals are
exposed which, if carelessly contacted, can cause serious shock or result in damage to the chassis. Maintain
interconnecting ground lead connections between chassis and picture tube dag when operating chassis.
Certain HV failures can increase X-ray radiation. Monitor should not be operated with HV levels exceeding the
specified rating for the chassis type. The maximum operating HV specified for the chassis used in this monitor is
26.5KV ±1KV
with a line voltage of 120/240 VAC. Higher voltage may also increase possibility of failure in HV supply.
It is important to maintain specified values of all components in the horizontal and high voltage circuits and
anywhere else in the monitor that could cause a rise in high voltage or operating supply voltages. No changes
should be made to the original design of the monitor. Components shown in the shaded areas on the schematic
should be replaced with exact factory replacement parts. The use of unauthorized substitute parts may create a
shock, fire or other hazard.
To determine the presence of high voltage, use an accurate, high impedance, HV meter connected between
second anode lead and CRT dag grounding device. When servicing the High Voltage System, remove static
charge from it by connecting a 20K ohm resistor in series with an insulated wire (such as a test probe) between
picture tube dag and 2nd anode lead.(AC line cord disconnected from AC power outlet.)
The picture tube used in this monitor employs integral implosion protection. Replace with tube of the same type
number for continue safety. Do not lift picture tube by the neck. Handle the picture tube only after discharging
the high voltage completely.

7
3. OPERATING INSTRUCTIONS
This procedure gives you instructions for installing and using the 9K color display.
1. Position the display on the desired operation and plug the power cord into a convenient AC outlet. Three-
wire power cord must be shielded and is provided as a safety precaution as it connects the chassis and
cabinet to the electrical conduit ground. If the AC outlet in your location does not have provisions for the
grounded type plug, the installer should attach the proper adapter to ensure a safe ground potential.
2. Connect the 15-pin color display shielded signal cable to your signal system device and lock both screws
on the connector to ensure firm grounding. The connector information is as follow:
15 - Pin Color Display Signal Cable
PIN NO. DESCRIPTION PIN NO. DESCRIPTION
1. RED 9. NC
2. GREEN 10. GND
3. BLUE 11. SYNC. GND
4. GND 12. SDA
5. GND 13. HORIZ. SYNC
6. GND-R 14.
VERT. SYNC (＊VCLK)
7. GND-G 15. SCL
8. GND-B
3. Apply power to the display by turning the power switch to the "ON" position and allow about thirty
seconds for display tube warm-up. The Power-On indicator lights when the display is on.
4. With proper signals feed to the display, a pattern or data should appear on the screen, adjust the brightness
and contrast to the most pleasing display.
5. This monitor has power saving function following the VESA DPMS. Be sure to connect the signal cable to
the PC.
6. If your 9K Series color display requires service, it must be returned with the power cord.
1
6
11 15
5
10

8
4. ADJUSTMENT
4-1ADJUSTMENT CONDITIONS AND PRECAUTIONS
1. Approximately 30 minutes should be allowed for warm up before proceeding.
2. Adjustments should be undertaken only on those necessary elements since most of them have been carefully
preset at the factory.
4-2 MAIN ADJUSTMENTS
NO. FUNCTION LOCATION DESIGNATION
1. B + ADJ PCB - MAIN VR902
2. SCREEN ADJ FLY BACK TRANS T402
3. FOCUS ADJ FLY BACK TRANS T402
4. ABL ADJ PCB - MAIN VR701
5. SUB-BRIGHTNESS ADJ PCB - MAIN VR702
4-3 ADJUSTMENT METHOD
1. B + & HV voltage adjustment and hold down circuit confirmation:
A. Chrome-2000 Signal generator or PC equivalent set mode 5, VGA 1024X768@85Hz pattern 1 .
B. Connect a DC Volt meter between TP902 or D925 cathode and ground, then adjust VR902 to be
133VDC(B+).
C. Connect a DC Volt meter between TP701(G1) and ground, Brightness set to max. Then adjust VR702 to
be -30 VDC.
D. Connect a 22kΩresistor in parallel with R419 to increase the HV, the hold down circuit will operate and
the display will disappear. Then disconnect this resistor to bring the unit to normal condition.
2. Factory preset Timings Adjustment:
A. Press MENU Key to show OSD window press Up or Down Key to switch the functional controls.
B. Press the Up Key to select the "ZOOM" function, then press the MENU Key. While do not release the
MENU Key until the OSD window changed to the Factory preset window.
C. The Factory preset window contains the following functional controls. Select one of the control by press
MENU key. Then press the Up/Down Key to adjust it's value for the optimum picture.
MENU Key to Quit the OSD window. Mean while the new setting data will be saved in the memory.
E. To switches the input signal to the other Timing Mode. Please follow step C ~ D to get the optimum picture.
F. Select the " " RETURN function and press the MENU Key, then the Factor Preset window will be
returned to the original OSD window.(user's operating condition)
G. The setting data of the CONTRAST, BRIGHTNESS, PIN-BALANCE, PARALLELOGRAM,
ROTATION, COLOR TEMPERATURE are common mode saved in the memory. Don't needed adjust it
individual at every timing Mode and save in the memory.
H Model select: for factory only, service engineer can't changed.

9
080
FACTORY PRESET
H: 36.51kHz V: 51.34Hz
VcVs
Tm
9300 6500
CONTRAST H-MOIRE REDUCE
BRIGHTNESS V-MOIRE REDUCE
H-CENTER R-GAIN
H-SIZE G-GAIN
V-CENTER B-GAIN
V-SIZE R-BIAS
ZOOM G-BIAS
TOP COMER R-BIAS
BOTTOM COMER 9300 COLOR TEMPERATURE
PINCUSHION 6500 COLOR TEMPERATURE
TRAPEZOID DEGAUSS
PIN-BALANCE OSD EXIT
PARALLELOGRAM RETURN
ROTATION
Vs LINEAR
HS SUB-H-SIZE
Vc LINEAR
HP H-SIZE-PHASE B/I ON/OFF
Tm Used time
B
TC
BI
BC
TC
BI
HS HP
H: 68.8KHz V: 85Hz
70

10
3. White Balance, Luminance adjustment:
A. Bias (Low Luminance) adjustment:
(a) Set mode 5 1024 x 768 Fh: 68.7KHz full white pattern.
(b) To make the adjustment condition is under the Factory preset window.
Same as step 2-C.
(c) Warm up more than 30 minutes.
(d) Brightness set to maximum. Contrast set to min. full white pattern, then adjust FBT screen
VR to make Y= 4.0±0.5cd/m2.
(e) Adjust G-Bias , B-Bias , R-Bias , to make the setting value is(20), then adjust the
R.G.B Bias individual to the color temperature x= 265 ±10, y= 290 ±10, Y= 4.0±0.5cd/m2.
B. Gain (High light) adjustment:
(a) Set mode 5 1024 x 768 Fh: 68.7KHz full white pattern.
(b) Brightness set to raster just cut off and set the contrast to max.
(c) Adjust G-Gain , B-Gain , R-Gain , to make color temperature x=283 ±10, y=297±
10, Y=140~150 cd/m2.
C. Recheck item A&B to make sure both of them in spec. Finally select OSD function to the 9300°K function,
then press the MENU Key. To make the setting data saved in the memory.
D. The adjustment of 6500°K white Balance, May follow step A ~ C , with the x=313 ±10, y=329 ±10,
Y=140~150 cd/m2.
E. Full white luminance:
(a) Set mode 5 1024 x 768 Fh: 68.7KHz full white pattern.
(b) Image Size : H:346±4mm V:260±4mm.
(c) Brightness set to raster just cut off and set the contrast to max.
(d) Adjust VR701 to the luminance at 90~95 cd/m2.
4. Focus Adjustment:
A. Set mode 5 1024 x 768 Fh: 68.7KHz with character full page.
B. Brightness to cut off and contrast to max.
C. Then adjust focus VR1 to a fine vertical line.
D. Adjust focus VR2 to a fine horizontal line.
E. Repeat step C & D..
5. Purity Adjustment
A. Be sure that the display is not being exposed to any external magnetic fields.
B. Ensure that the spacing between the Purity, Convergence, Magnet, (PCM), assembly and the CRT stem is
29mm .(See below diagram)
C. Produce a complete, red pattern on the display. Adjust the purity magnet rings on the PCM assembly to
obtain a complete field of the color red. This is done by moving the two tabs in such a manner that they
advance in an opposite direction but at the same time to obtain the same angle between the two tabs, which
should be approximately 180'.
D. Check the complete blue and complete green patterns to observe their respective color purity. Make minor
adjustments if needed.

11
RELATIVE PLACEMENT OF TYPICAL COMPONENTS
Purity Magnets
Deflection Yoke
4-pole Convergence Magnets
6-pole Convergence Magnets
6. Convergence adjustment
A. Produce a magenta crosshatch on the display.
B. Adjust the focus for the best overall focus on the display.
Also adjust the brightness to the desired condition.
C. Vertical red and blue lines are converged by varying the angle between the two tabs of the 4 pole magnets
on the PCM assembly. (See above diagrams)
D. Horizontal red and blue lines are converged by varying the two tabs together, keeping the angle between
them constant.
E. Produce a white crosshatch pattern on the display.
F. Vertical green and magenta lines are converged by varying the angle between the two tabs of the 6-pole
magnets.
G. Horizontal green and magenta lines are converged by varying the two tabs together, keeping the angle
between them constant.
5. CIRCUIT DESCRIPTION
5-1 MICRO CONTROLLER CIRCUIT
MICRO Controller
The IC101 contains a 6502 8-bit CPU core, 256 bytes of RAM, 16K bytes of ROM,14 channel 8 bit PWM D/A
converters, 2 channel A/D converters for key detection, one 8 bit pre-loadable base timer, internal H-sync and V-
sync signals processor providing mode detection, watch- dog timer preventing system from abnormal operation,
and an I2C bus interface.
H/V sync signals processor
The functions of the sync processor include polarity detection, H-SYNC & V-SYNC signals counting,
Programmable SYNC signals output, free running signal generator. Pin41/Pin42 are for the H-SYNC and V-
SYNC input, Pin33/Pin34 will output the same signal as input sync signal without delay, and the polarity are
setting in the positive. When no signal input, the Pin33 will output a 61HZ V-SYNC free run signal. The Pin34
will output a 62.5KHz H-SYNC free run signal. for the monitor testing use.

12
On Screen Display Controller
The IC804 is designed for display the built-in characters or fonts onto monitor screen. The display operation is by
transforming data and control information from micro controller to RAM through a serial data interface.
Pin 2 is used to control the internal oscillator frequency by DC voltage input from external low pass filter (R830,
C811, R833) and filter (R126, C115) is used to regulate the appropriate bias current for internal oscillator the
resonate at specific dot frequency.
Pin5 is input the horizontal fly back pulse, for PLL generator tracking.
Pin6 is left floating, I2C bus is enabled. Otherwise the SPI bus is enabled.
Pin7 the external data transfer through this pin to internal display registers and control registers
Pin8 the clock-input pin is used to synchronize the data transfer.
Pin10 is input the vertical flyback pulse for synchronizing the vertical position.
Pin12 is output a blanking signal to cut off external R.G.B signals of VGA while this chip is displaying characters
or windows.
Pin13, Pin14, Pin15 is used to output the OSD (B.G.R) video signal.
5-2 DEFLECTION CIRCUIT
The deflection circuit is achieved by a high performance and efficient solution IC 401 (UPC1888ECT) for this
monitor. The concept is fully DC controllable and can be used in applications with a micro-controller solutions.
The UPC1888ECT provides sync. Processing with full auto sync. capability, a flexible SMPS block and an
extensive set of geometry control facilities. Further the IC generates the drive waveforms for DC coupled vertical
boosters to the TDA9302H .
Horizontal Oscillator
The oscillator is of the relaxation type and requires a capacitor of 390nF C403 at pin 23. The maximum oscillator
frequency is determined by a resistor R443 from pin 22 to ground.
PLL2 Phase Detector
This phase detector compares the line flyback pulse at pin 18 with the oscillator saw-tooth voltage. The HFL0
detector thus compensates for the delay in the external H-deflection circuit by adjusting the phase of the HDRV
output pulses. The phase between H-flyback and H-sync can be controlled at pin21.
X-ray Protection
The X-ray protection input pin 19 provides a voltage detector with a precise threshold. If the voltage exceeds this
threshold for a certain time, an internal latch switches the whole IC into protection mode. In this mode several pins
are forced into defined states:
Pin17 (HDRV) is floating
Pin 12 (BDRV) is floating
Vertical Oscillator
The vertical free –running frequency is determined by the capacitor C604 at pin 2 and resistor R608 at pin20.
Usually the free-running frequency should be lower than the minimum trigger frequency.

13
5-3 TRANSISTOR & DIODE CIRCUIT
LOCATION
FUNCTION AL DESCRIPTION
D101 For C102 Discharge
D405 Speed up for Q403
D406 Supply a bias for D408
D408 Damping Diode and Modulation Diode
D414~ D416,D418 Buffer Diode for Q412, Q417, Q418, Q420
Q401 B+ Mute Control
Q402 Horizontal Driver
Q403 Horizontal Out Put
Q404, Q406 A differential Amp for Drive Q405
Q405 Darlington Transistor for H-Size Control
Q407 Horizontal Linearity Correction Control
Q410,Q412,
Q417,Q418
Horizontal S-Correction Control
D707 Mixing Diode
D704 Rectifier for 250V Supply
D709 Protection Diode for Q708
D706,D708 Rectifier for -200V Supply
Q707 Picture Mute Control AMP
Q703, Q706 Brightness Control CKT
Q708 Vertical Dynamic Focus Control AMP
DB901 Bridge Rectifier for AC Source
D918 ~ D919 Rectifier for Output Voltage Supply
D921 ~ D923 Rectifier for Output Voltage Supply
D924 Clip Diode for Trigger CKT
D925 Rectifier for B+ Supply
D926, D927 Raster Position Control
D939 Clip Diode for Snuffer Pulse
ZD901 Protection Diode
ZD903 Protection Diode
Q911 MOS FET for B+ Control
Q912, Q915 Push Pull Driver for Q911
Q914 Pre-Amplifier for Q912, Q915
Q850 ~ Q852 DC Restoration for CRT Bias Adjustment

14
6.TROUBLE SHOOTING CHART
6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS
REFER ITEM S.M.P.S.
CHECK CRT'S HEATER RELATIVE
CIRCUIT
BRIGHTNESS SET TO MAX.
THEN CHECK CRT G1 VOLTAGE
NG
NG
NG
NG
NG
OK
OK
OK
OK
OK
CHECK THE HIGE VOLTAGE
CHECK THE VOLTAGE OF CRT
HEATER ABOUT 6.3V
CHECK VOLTAGE OF THE CRT
CHECK BRIGHTNESS CIRCUIT
OK
CHECK POWER SAVING CIRCUIT,
"ABNORMAL DISPLAY"
H-SYNC, V-SYNC SIGNAL
REFER ITEM 8-2
CATHODE ABOUT 60V TO 70V
CHECK SCREEN VOLTAGE ABOUT
400V TO 700V
OF CRT ABOUT 25.5 ~ 26.5KV
LESS THAN 300V CHECK FBT
CHECK MAIN PCB POWER SUPPLY
60.5V, 14.5V, 80V
CHECK FAILSAFE CKT IC401
PIN 2 RELATIVE CKT.
Q703, Q706, Q707 RELATIVE CKT.
26.5~27.5KV
CHECK MAIN PCB POWER
SUPPLY 137.5V,14.5V,80V
CHECK THE HIGE VOLTAGE
OF CRT ABOUT 25.5~27.5KV

15
2.ABNORMAL VIDEO LEVEL ON SCREEN
CHECK 12V RELATIVE
CIRCUIT
OK
NG
OK
NG
NG
OK
OK
CHECK THE VOLTAGE OF IC801
CHECK THE SIGNAL INPUT OF R.G.B.
ABOUT 0.7Vpp
CHECK THE VIDEO OUTPUT OF IC801
R.G.B. APPROACH STANDARD
CHECK SIGNAL CABLE OR
INTERFACE CARD.
CONTRAST SET MAX.
OR IC401 PIN 16 OUTPUT
CHECK IC801 PIN 13 ABOUT 4V
PIN 6, 9, 22 ABOUT 12V
CHECK IC801 PIN 15 CLAMP PULSE
PIN 18, 20, 23 ABOUT 4Vpp,
CHECK THE IC105 RELATIVE CIRCUIT
PIN 16 BLANK PULSE
PIN 26, 27, 28 ABOUT 4V OR
CHECK Q801 AND RELATIVE CKT
3. ABNORMAL DDC (PLUG & PLAY)
OK
NG
CHECK IC101 PIN 5 VOLTAGE ABOUT 5V
CHECK SIGNAL CABLE
OR H802 PIN 3, 4 DATA OUTPUT
CHECK Q102 GOOD OR FAIL
16,19,22
7,15.18,21 ABOUT 12V
11
5
1~24

16
6-2 ABNORMAL DISPLAY
1.NO SIGNAL ON SCREEN
CHECK FBT RELATIVE
CIRCUIT
LESS THAN 400V
OK
NG
NG
OK
OK
NG
OK
NG
CHECK THE OUTPUT VOLTAGE
CHECK THE B+ VOLTAGE OF
CHECK THE VOLTAGE OF CRT
CATHODE ABOUT 40Vpp
CHECK THE VOLTAGE OF FBT SCREEN
CHECK THE RELATIVE CIRCUIT
CHECK THE 12V PIN
OF SMPS ON MAIN PCB
RELATIVE CIRCUIT
OF P802 CONNECTOR
ABOUT 400V TO 700V
EXCEED 700V
OF IC801
CHECK FBT & CRT RELATIVE CIRCUIT
OR REFER ITEM 7-1
VIDEO PCB ABOUT 80V
CHECK THE 80V RELATIVE CIRCUIT
CHECK VIDEO IC801 VCC ABOUT 12V
OF IC801 PIN 18, 20, 23 ABOUT 3Vpp
CHECKTHE VQ802 ~ Q807
16,19,22
Check IC803 Pin1,2,3
ABOUT 40V

17
6-3 NO BLANKING
NG
OK
CHECK THE RELATIVE
CIRCUIT OF BLANKING
CHECK THE RELATIVE CIRCUIT
ON MAIN PCB
CHECK G1 RELATIVE CIRCUIT
CHECK IC801 PIN 16 ON VIDEO PCB,
Q705, R718, C707 ON MAIN PCB
OF C433, D410, R635, R636, IC105
6-4 HOR./OSC/DEF/HV CIRCUIT FAULT
1. NO RASTER (DISCONNECT WITH SIGNAL CABLE)
NG
OK
OK
OK
NG
NG
NG
CHECK THE COLLECTOR VOLTAGE
CHECK THE COLLECTOR VOLTAGE
RELATIVE CIRCUIT
RELATIVE CIRCUIT
CHECK IC401 PIN 26 ~ 31
CHECK Q402, T401
CHECK T401, T402, Q402, Q403,
OF Q402 ABOUT 40Vpp
OF Q403 ABOUT 1100Vpp AT FH:31KHz
D408, C418, C419, H-DY
CHECK IC401 PIN 10 ABOUT 11.5 VDC
CHECK IC401 PIN 8 WAVE FORM
ABOUT 10Vpp
CHECK IC401 PIN 10 RELATIVE CIRCUIT
CHECK IC401 PIN 16 ABOUT
11.5VDC
CHECK IC401 PIN 16
RELATIVE CIRCUIT
CHECK IC401 PIN 17 WAVE
FORM ABOUT 0.7Vpp
CHECK THE COLLECTOR
VOLTAGE OF Q402 ABOUT 18Vpp

18
6-5 ABNORMAL HORIZONTAL DEFLECTION
1. ABNORMAL HORIZONTAL WIDTH OF VIDEO
NG
OK
CHECK THE RELATIVE CIRCUIT
CHECK THE RELATIVE
CIRCUIT OF SMPS.
READJUST H-WIDTH FUNCTION
OF Q404, Q405, & Q406
CHECK THE HV OF
CHECK FBT B+ VOLTAGE
Q911, Q912, Q914, Q915 &
IC401 PIN 4, 5, 6, VR 902
ABOUT 60.5V AT FH=31KHz
CRT ABOUT 26KV
2. ABNORMAL HORIZONTAL RASTER CENTER
P403 AND JUMPER
CHECK T903, D926, D927, R964, R968
3. ABNORMAL HORIZONTAL VIDEO CENTER
CHECK IC101 PIN 9, 10, IC401 PIN 18, 19
4. ABNORMAL HORIZONTAL LINEARITY
CHECK L401, Q407, R447, C448
AND IC101 PIN 20, 21, 22, 23
CS SWITCHER IC403, Q410, Q411, Q420
137V
CHECK L401, Q407, Q407, R447, C448 AND IC101
PIN 20,21,22,23 CS SWITHCHER IC403, Q401,
Q412,Q417
NG
OK

19
6-6 ABNORMAL VERTICAL SCANNING
1. ABNORMAL VERTICAL SIZE
OK
NG
OK
NG
READJUST V-SIZE FUNCTION VALUE
RELATIVE CIRCUIT
CHECK VERT. OSC CIRCUIT
RELATIVE CIRCUIT
NG
CHECK THE IC601 PIN 7 ABOUT 40V
CHECK IC601 PIN 6 OUTPUT ABOUT
38Vpp
CHECK ZD601, ZD602 R626 & SMPS
CHECK IC401 PIN 22, 23, 24
CHECK IC401 PIN 12, 13
2. VERTICAL CENTER
NG
READJUST V-CENTER
CHECK IC101 PIN 9, 10
IC401 PIN 18, 19
6-7 SIDE-PIN CUSHION DISTORTION
NG
READJUST SIDEPIN
CHECK IC401, Q404, Q405, Q406
RELATIVE CKT.
READJUST V-SIZE FUNCTION
VALUE CHECK THE IC601 PIN 6
ABOUT 12V
CHECK D601, R616 & SMPS
RELATIVE CIRCUIT
CHECK IC401 PIN 2,20
CHECK IC601 PIN 6 OUTPUT
ABOUT 45Vpp CHECK IC401 PIN 4
RELATIVE CIRCUIT