Akira LCT-20CVST Schematic
LCT TV
Service Manual
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MODEL:
LCT-20CVST
Model No.: LCT-20CVST
Version: 1.0
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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
Model No.: LCT-20CVST
Version: 1.0
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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)
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Video Input 2(Composite RCA 3Pin, Included Audio 2Pin)
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DVD Input (Y Cb Cr, RCA 3Pin)
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S-Video Input
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EURO Scart Jack
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Headphone Output (Phone Jack, Stereo)
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A/V Output (Scart Jack)
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Model No.: LCT-20CVST
Version: 1.0
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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)
PC
INPUT
OUTPUT
POWER
Model No.: LCT-20CVST
Version: 1.0
DVD Level
Sound Level 1.4±0.2Vp_p
A/V OUT Level 2±0.1Vp_p
Sound Speaker RMS 5W*2
LIPS
Power Consumption 60W
Analog RGB 0.7±0.1Vp_p (75Ω)
H Frequency 31KHz
V Frequency 56~85Hz
Y: 1Vp_p
Cb: 0.7Vp_p
Cr: 0.7Vp_p
(0.5Vrms)
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
Out Current Min 0A~Max2A
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Available PC input mode & Video timing standard
Mode Resolution Horizontal
Frequency
(KHz)
720 x 400 31.469 70.087 28.322 -/+
640 x 480 31.469 59.940 25.175 -/-
VGA
640 x 480 37.861 72.809 31.500 -/-
640 x 480 37.500 75.000 31.500 -/-
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
Vertical
Frequency
(Hz)
Pixel Clock
Frequency
(MHz)
Sync Polarity
(H/V)
Model No.: LCT-20CVST
Version: 1.0
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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 )
Model No.: LCT-20CVST
Version: 1.0
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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)
Model No.: LCT-20CVST
Version: 1.0
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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.
Model No.: LCT-20CVST
Version: 1.0
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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.
Model No.: LCT-20CVST
Version: 1.0
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PCB ASSEMBLY FUNCTIONAL DESCRIPTION
A/D Board
Display conversion A/D Board assembly (champion Junior) connector location:
Reference Description Pin Connector Type 4
JA360 Analog RGB input 15 Pin D-sub jack
JAS1 Euro scart input Scart jack (2202-21T)
JA203 PC-audio input Ear-phone jack (EJ310CD-5-A 3.5¢)
JA301A S-Video input S-Video jack
JA202 Video input RCA 1P jack
JA201 Sound input RCA 4P jack
JA204 Video 2/ DVD input RCA 4P Jack
JA206 Head phone output Ear-phone jack (EJ310CD-5-A 3.5¢)
CN21M Tuner connector 8 Moles 53014-08
CN70M Inverter connector 12 Molex53015-12
CN01M OSD Control connector 8 Molex53015-08
CN002 RS232 Control connector (option) 4 Molex 53015-04
CN25M Speaker Connector 4 Molex 53015-04
CN72M Interface connector 40 PH03-40DS-G
CN21M (tuner connector)
Pin No Symbol Description
1 VCC +5V
2 GND GND
3 SDA 12C serial data
4 SCL 12C serial clock
5 GND GND
6 CVBS CVBS out
7 GND GND
8 SIF Sound IF out
Model No.: LCT-20CVST
Version: 1.0
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CN70M (inverter connector)
Pin No. Symbol Description
1 VCC
2 VCC
3 VCC
4 NC
5 PWSEL Select of luminance control signal method
6 BRTP PWM signal
7 BRTI Luminance control by voltage method
8 BRTC Backlight ON/OFF signal
9 NC
10 GND
11 GND
12 GND
CN25M (speaker connector)
Pin No. Symbol Description
1 R+ Speaker out right
2 R- GND
3 L- GND
4 L+ Speaker out left
CN72M (interface connector)
Pin No. Symbol Description
1 VLCD +12Vcc
2 VLCD +12Vcc
3 RA0 Red Data (LSB)
4 RA1 Red Data
5 RA2 Red Data
6 RA3 Red Data
7 RA4 Red Data
8 RA5 Red Data
9 GND Ground
10 GND Ground
11 RA6 Red Data
+24V
GND
Model No.: LCT-20CVST
Version: 1.0
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Pin No. Symbol Description
12 RA7 Red Data (MSB)
13 GA0 Green Data (LSB)
14 GA1 Green Data
15 GA2 Green Data
16 GA3 Green Data
17 GND Ground
18 GND Ground
19 GA4 Green Data
20 GA5 Green Data
21 GA6 Green Data
22 GA7 Green Data (MSB)
23 BA0 Blue Data (LSB)
24 BA1 Blue Data
25 GND Ground
26 GND Ground
27 BA2 Blue Data
28 BA3 Blue Data
29 BA4 Blue Data
30 BA5 Blue Data
31 BA6 Blue Data
32 BA7 Blue Data (MSB)
33 GND Ground
34 GND Ground
35 LVSYNC Vertical sync
36 LCKA Dot Clock
37 GND Ground
38 GND Ground
39 LHSYNC Horizontal Sync
40 LDTC Data Enable
Model No.: LCT-20CVST
Version: 1.0
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OSD Control Board
OSD Key Pad Control Board Assembly.
The Control Board assembly is the OSD user control /interface.
Control PCB connector and switch identification.
Reference Description Connector type
Sw1 POWER IT-1102AH-T
Sw2 SELECT IT-1102AH-T
Sw3 VOL+ IT-1102AH-T
Sw4 VOL- IT-1102AH-T
Sw5 CH+ IT-1102AH-T
Sw6 CH- IT-1102AH-T
Sw7 Menu IT-1102AH-T
LED LED SAM3270
RM03 Remocon reciver Rom-N338TM2
CNC01 OSD Connector MOLEX 53015-0810
Tuner board
Tuner control board assembly
Model No.: LCT-20CVST
Version: 1.0
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