akira LCT-20CVST User manual

LCT TV
Service Manual

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Model No.: LCT-20CVST
Version: 1.0
MODEL:
LCT-20CVST

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Model No.: LCT-20CVST
Version: 1.0
CONTENTS
SPECIFICATION..................................................................................................................................... 4
ADJUSTMENT SPECIFICATION.......................................................................................................... 8
PCB ASSEMBLY FUNCTIONAL DESCRIPTION ............................................................................. 11
BLOCK DIAGRAM .............................................................................................................................. 16
IMPORTANT IC LIST........................................................................................................................... 17
TROUBLE SHOOTING ........................................................................................................................ 18
EXPLODED VIEW................................................................................................................................ 22
PART LIST............................................................................................................................................. 30
CIRCUIT DIAGRAM............................................................................................................................ 32

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Model No.: LCT-20CVST
Version: 1.0
SPECIFICATION
LCD Panel
 LG-Philips LCD Panel : LC201V02-A3
 Active Screen Size : 20.1 inches (584.40m/m) diagonal
 Outline Dimension : 432(H) x 331.5(V) x 25.0(D)mm(Typ)
 Pixel Pitch : 0.6375mm x 0.6375 x RGB
 Pixel Format : 640 horiz. By 480 Vert. Pixels RGB strip arrangement
 Color Depth : 8bit, 16.7M Colors
 Luminance, White : 450 cd/
 Response Time : 25msec (Rise 13ms + Decay 12ms)
 Viewing Angle : R/L 176 Degree, U/D 176 Degree
 Backlight Assembly : 6 CCFL
 Contrast Ratio : 350 : 1
In/Out Jack
 Power Input : AC100 ~ 240V 50 ~ 60Hz
 Antenna Input : 75 Ohm Unbalanced Coaxial Cable
 PC Input : 15 Pin D-sub Jack(Female Type) – RGB Analog Input, Included Main Board
 PC Audio Input : Phone Jack(Stereo) – From PC, Included Main Board
 Video & Audio In/Out – Included Sub Board
- Video Input 1(Composite RCA 3Pin, Included Audio 2Pin)
- Video Input 2(Composite RCA 3Pin, Included Audio 2Pin)
- DVD Input (Y Cb Cr, RCA 3Pin)
- S-Video Input
- EURO Scart Jack
- Headphone Output (Phone Jack, Stereo)
- A/V Output (Scart Jack)

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Model No.: LCT-20CVST
Version: 1.0
User Interface
 7 Panel Key
 Power , Menu , Select , Vol Up , Vol Down , CH Up , CH Down
 3 Color LED
 Red : Stand by Condition
 Green : Power On Condition
 Yellow : SLEEP TIME On Condition
 Remocon Receiver
 Remocon (42Key )
 On Screen Display
 Control using OSD
 OSD Language : English, Arab
 Plug & Play : DDC - 1/2B
 Factory Mode
 Mode for controlling the adjustment item & Panel Option in mass production
Electrical specification
In /Out Items Sub Items Specification
Video 1, 2 Level 1±0.1p_p (75Ω)
Analog RGB 0.7±0.1Vp_p (75Ω)
H Frequency 31KHz
PC
V Frequency 56~85Hz
Y: 1Vp_p
Cb: 0.7Vp_p
DVD Level
Cr: 0.7Vp_p
INPUT
Sound Level 1.4±0.2Vp_p
(0.5Vrms)
A/V OUT Level 2±0.1Vp_p
OUTPUT Sound Speaker RMS 5W*2
Input Voltage AC 90~265 Vac
Input Frequency 47~63Hz
Output 1 Voltage DC 14.5~15.5V
Out Current Min 30mA~Max 2A
Output 2 Voltage DC 10.8~15V
LIPS
Out Current Min 0A~Max2A
POWER
Power Consumption 60W

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Model No.: LCT-20CVST
Version: 1.0
Available PC input mode & Video timing standard
Mode Resolution Horizontal
Frequency
(KHz)
Vertical
Frequency
(Hz)
Pixel Clock
Frequency
(MHz)
Sync Polarity
(H/V)
720 x 400 31.469 70.087 28.322 -/+
640 x 480 31.469 59.940 25.175 -/-
640 x 480 37.861 72.809 31.500 -/-
640 x 480 37.500 75.000 31.500 -/-
VGA
640 x 480 43.269 85.008 36.000 -/-
OSD Specification
 PICTURE
 CONTRAST
 BRIGHTNESS
 COLOR TEMPERAT ( PC input mode only )
 STANDARD , 6500K , USER, RESET , 9300K
 SHARPNESS ( Not Available PC MODE )
 COLOR ( Not Available PC MODE )
 SOUND
 TREBLE
 BASS
 BALANCE
 S.MODE
 GEOMETRY ( PC input mode only )
 H-POSITION
 V-POSITION
 AUTO POSITION
 FUNCTION
 TRACKING ( PC input mode only )
 AUTO TRACKING
 CLOCK
 PHASE
 INFORMATION
 TUNING ( TV input mode only )
 SORT
 AUTO TUNING
 MANUAL TUNING
 FINE TUNING
 CH SKIP
 LANGUAGE

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Model No.: LCT-20CVST
Version: 1.0
Factory Mode OSD Specification
 How to use Factory Mode
 Press Power & Select Key in Panel Control key, and go to Factory mode.
 Factory ADJ
 CLOCK DELAY
 AUTO COLOR GAIN
 OPTION
 MX88L281 1
 MST9883 1 ( PC input mode only )
 MST9883 2 ( PC input mode only )
 SUB C VCO
 SUB C CHG CURRENT
 INIT VCO CURRENT
 VPC3230 ( excluding PC MODE )
 CONTRAST
 BRIGHTNESS
 PEAKING
 CIP CONTRAST
 CIP BRIGHT
** In mass production, adjust only Factory ADJ item, do not adjust other Modes. ( In the time of
variation of A/S & initial condition of screen quality , built in other Modes for controlling )

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Model No.: LCT-20CVST
Version: 1.0
ADJUSTMENT SPECIFICATION
Adjustment instruction of CLOCK DELAY
1. Adjustment item: Adjust the dispersion happening in the time of matching ASSY-MAIN and LCD
PANEL. (As the contact status of the CONNCETOR for connecting LCD PANEL, dispersion
happens)
2. Adjustment Process: After assembling the SET, do the adjustment.
3. Preliminary adjustment:
1) Connect the outlet VIDEO PATTERN GENERATOR (ANALOG RGB &
SEPARATE H, V OUT) to INPUT (15PIN D-sub with VGA CABLE)
2) TEST PATTERN: 1DOT MOIRE PATTERN.
3) Select Output FORMAT into 640 x 480 @60HZ.
4) Turn on the SET, and them select in PC MODE.
4. Adjustment Instruction:
1) Press SEL & Power Key in Front panel at the same time , go to Factory mode
2) Select CLOCK DELAY (including in FACTORY ADJ MENU) with CH UP/DOWN
KEY in Factory mode
3) Changing the level of CLOCK DELAY with VOL UP/DOWN KEY, adjust to the
noiseless level in screen (variable range : 0 ~ 15, DEFAULT : 15)

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Model No.: LCT-20CVST
Version: 1.0
Adjustment Instruction of AUTO COLOR GAIN
1. Adjustment Item: Function of automatically setting ADC LEVEL of AD9884 with ANALOG RGB
(D-sub) signal. (WHITE BALANCE & CONTRAST adjustment)
2. Adjustment Process: After assembling the SET, do the adjustment.
3. Preliminary Adjustment
 Connect Outlet of VIDEO PATTERN GENERATOR to the input terminal of D-SUB.
 TEST PATTERN : Select COLOR BAR PATTERN
 Turn on the SET, and then select in PC MODE.
4. Adjustment Instruction
 Press SEL & Power Key in Front Panel at the same time, and go to Factory mode.
 In Factory mode, select Auto Color Gain in Factory ADJ.
 Press VOL UP KEY, and then displaying the phrase " Processing ", AUTO
Adjustment start
 When adjustment is completed, the phrase " Processing " disappears
 Caution: In the course of Processing, do not remove the signal.
Setting Instruction for OPTION
1. OPTION : - X2 - BYPASS
 Using 6 BIT PANEL
 Back-Light Control of Inverter
(Bright Max: LOW, Min : HIGH)
2. OPTION : - X2 - INVERT
 Using 6 BIT PANEL
 Back-Light Control of Inverter voltage polarity
(Bright Max : HIGH, Min : LOW)
3. OPTION : - X3 - BYPASS
 Using 8 BIT PANEL
 Back-Light Control of Inverter voltage polarity
(Bright Max : LOW, Min : HIGH)
4. OPTION : - X3 - INVERT
 Using 8 BIT PANEL
 Back-Light Control of Inverter voltage polarity
(Bright Max : HIGH, Min : LOW)
*** Select no 4 in the case that no 4 is not selected.

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Model No.: LCT-20CVST
Version: 1.0
Adjustment Instruction of VPC3230
1. Adjustment item: Function of adjusting DEFAULT VALUE of VPC3230 DEVICE.
2. Adjustment process: After assembling the SET, do the adjustment .
3. Preliminary adjustment
 Connect Outlet of VIDEO PATTERN GENERATOR to the input terminal of CVBS.
 TEST PATTERN : Select COLOR BAR PATTERN
 Turn on the SET, and then select in VIDEO MODE.
4. Adjustment Instruction
 Press SEL & Power Key in Front Panel at the same time, and go to Factory mode.
 Select VPC3230 in Factory mode.
 Adjust to the following levels with VOLUME UP/DOWN, CH UP/DOWN
a. CONTRAST 52
b. BRIGHT 9
c. PEAKING 0
d. CIP CONTRAST 12
e. CIP BRIGHT 7
*** No need to adjust when the SET is stable.