akira LCT-15CH12ST User manual

LCD TV
Service Manual

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Model No.: LCT15CH12ST.doc
Version: 1.0
MODEL:
LCT-15CH12ST
CHASSIS
INFO: LS-07

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Model No.: LCT15CH12ST.doc
Version: 1.0
CONTENTS
SAFETY PRECAUTION.........................................................................................................................4
MAIN FEATURE.....................................................................................................................................6
ELECTRIC CIRCUIT..............................................................................................................................9
MAIN ICs FUNCTION..........................................................................................................................10
SYMPTOMS & CORRECTION............................................................................................................24
LIST OF BREAKABLE & MAINTENANCE PARTS..........................................................................25
FACTORY MODE .................................................................................................................................27
EXPLODED VIEW................................................................................................................................28
PART LIST ...........................................................................................................................................29
WIRING DIAGRAM.............................................................................................................................30
CIRCUIT DIAGRAM............................................................................................................................31
WALL-MOUNTING BRACKET INSTALLATION GUIDE................................................................38

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1.
IMPORTANT SAFETY PRECAUTION
Model No.: LCT15CH12ST.doc
Version: 1.0

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Model No.: LCT15CH12ST.doc
Version: 1.0

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Model No.: LCT15CH12ST.doc
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MAIN FEATURE
RF input ,CATV function
Capable to receive the full append cable programs in 470MHZ, can
store 100 programs (Program number display 0～99);
AV Audio and AV Video input
In SCART mode, the system can automatically activate SCART
checking function to identify signal input modes(CVBS or RGB) and
input signal character(16:9 or 4:3); Capable to receive PAL, NTSC,
SECAM color systems; Very convenient to watch VCR (video
cassette recorder), Pickup Camera and other Disc’s programs.
YPbPr input
Can receive high definition YPbPr component video signal from
such as DVD Conveniently . Support format:480I、480P、576I、576P、
720P（50/60HZ）、1080I（50/60HZ）、1080P（50/60HZ）；
VGA input
As the Terminal display Equipments of computer, it can connect with
computer conveniently. it can connect with Computer audio card by
its own Audio connection line ,so you can listen the audio
information from computer.
Program lock and child lock function
The function of program lock can lock the programs、input password
and Modification, the function of child lock can lock the keys.
Timer function
You can set turn on and turn off on time, and power off in 15 min
automatically if no signal input. Automatically enter into save energy
mode by itself if no signal in PC condition, it can be awaken if signal
inputs.
Blue screen mute noise
In condition of TV、AV、RGB and YPbPr, gentle blue screen will be

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displayed if no signal input.
Chinese/English menu
Adopt the design of Convenient and Simple graphic menu, you can
operate menu more conveniently and more intuition.
Save energy function(power management mode)
When TV is used as PC display terminal, and PC has no output
signal . The TV will be power off in about 30 Seconds automatically,
and enter into standby condition. press down Power/P+/P-/ Number
key of Remote control or the PC signal appearance again, the TV
will be on automatically.
Plug-and-play
The TV works as the terminal Equipments of computer, need not
equip install software，it is real Plug-and-Play.
Automatic correct
By its automatic correct function ,the LCD TV can bring you the best
view.
No Flicker、no Radiation 、Green environmental protection
Because of it’s Advanced power Management mode, the TV can
realize standby and recall on function.
ACI function ( Auto channel Installation ).
Stereo and digital accompanying sound processing.
Auto identify and demodulate IGR, and decode NICAM digital
accompanying sound.
Zoom image function
Support follow zoom function: Full screen mode、4:3 mode（16:9
TFT）,16:9（4：3 TFT）、Movie mode、Sub-title movie mode.
Light weight、small dimension、Low power consumption
Advanced picture quality Strengthen function
Dynamic skin color Correct: Improve distort color in picture, make it

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Near to real color.
Black level Extension: blacken the more black area of picture, Raise
the contrast in Dark Background.
Color Edge correct: Increase the Steep of color signal edge ,make
the edge of color Transition more clearly .
Brightness edge correct: increase the steep of Brightness signal
edge, make the edge of picture is more clearly.
Super fine and inner fairness TFT
10-page teletext storage
Dynamic comb filter
Headphones output

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Model No.: LCT15CH12ST.doc
Version: 1.0
ELECTRIC CIRCUIT
The LS07 chassis LCD TV is composed of steady voltage circuit、inverter Circuit 、RF circuit、video Strengthen circuit、video
Processing circuit、Power Enlarge circuit、VGA circuit、system control circuit and key control circuit. The block diagram of circuit
Constitute as below:

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Model No.: LCT15CH12ST.doc
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MAIN ICs FUNCTION INTRODUCTION
GENERAL INTRODUCTION
No. Name Model Main Function
1 A1 TAF5-E2I21RW2 RF tuner
2 U8、U21 TDA1517AWT Audio amplifier
3 U3 MST518 AD converter and format change
4 U2 UOC(TDA15021H) Video decode and MCU control
5 Q9 Si2311DS MOS switch
6 U11、U12 IRF7316 MOS switch
7 U19 NTMS10P02 MOS switch
8 U23 LM2596-5.0 Liner voltage IC
9 U1 24LC21A EEPROM(save display parameter
information)
10 U4 24LC32A
EEPROM（save user control information）
11 U6、U20 PI5V330A Video switch

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Model No.: LCT15CH12ST.doc
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1. MST518 High Integration Chip:
MST518 is a high performance、high integration image processor which is
designed for LCD, it can support SXGA format (1280*1024).it integrates a
group of AD converter 、high quality format transform system、OSD generator、
output clock generator、multiple format output display interface (support TTL、
LVDS、RSDS)
MST518 feature:
zHave high quality Expand transform and compress transform, can
output XGA format signal
zIntegrated LVDS circuit inside
z8 bit high quality ADC inside
zDouble VGA input, Software switch
zSupport ITU-656 format signal input
zSupport H/V sync、composite sync、green composite sync input, and
detect automatically by itself
zProgrammable 10 bit Gamma correct, the brightness and contrast is
adjustable
z8 color、256 Character OSD
zBuilt-in DDC circuit inside
zLow standby power
Support TTL、double LVDS signal output, Software switch
MST518 Pin Function:
Pin Definition Pin Function
CPU Interface
33 HWRESET Hardware reset，high voltage enable
82 Chip select signal of three-wire serial bus
83 data signal of three-wire serial bus
84 SCL clock signal of three-wire serial bus
85 INT interrupt
98-91 AD [7:0] Parallel bus，the chassis is not used
125 BUSTYPE Bus type select
Analog Interface
38 HSYNC0 Analog Horizontal sync signal input channel 0
39 VSYNC0 Analog vertical sync signal input channel 0
40 HSYNC1 Analog Horizontal sync signal input channel 1
41 VSYNC1 Analog vertical sync signal input channel 1
78 RMID Scalar internal reference. voltage
79 REFP internal ADC decouple ＋
80 REFM internal ADC decouple －
75 RIN0 Analog red signal input channel 0
74 RIN0M Analog red signal input channel 0 re-grounding
voltage
73 SOGIN0 Green sync signal input channel 0
72 GIN0 Analog green signal input channel 0
71 GIN0M Analog green signal input channel 0
re-grounding voltage
70 BIN0 Analog blue signal input channel 0
69 BIN0M Analog blue signal input channel 0
re-grounding voltage

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66 RIN1M Analog red signal input channel 1 re-grounding
voltage
65 RIN1 Analog red signal input channel 1
64 GIN1M Analog green signal input channel 1
re-grounding voltage
63 GIN1 Analog green signal input channel 1
62 SOGIN1 Green sync signal input channel 1
61 BIN1M Analog blue signal input channel 1
re-grounding voltage
60 BIN1 Analog blue signal input channel 1
55 REXT Outside connect 390with 3.3V
LCD Interface
145 OCLK Clock output
146 LDE enable signal
144 LVSYNC vertical sync output
143 LHSYNC Horizontal sync output
138 LVA0M
LVDS output 0－
137 LVA0P LVDS output 0+
136 LVA1M
LVDS output 1－
135 LVA1P LVDS output 1+
134 LVA2M
LVDS output 2－
133 LVA2P LVDS output 2+
128 LVA3M
LVDS output 3－
127 LVA3P LVDS output 3+
132 LVACKM
LVDS clock signal output－
131 LVACKP LVDS clock signal output +
26-23,18-15 RB[7:0] TTL red signal channel
14-11, 8-5 GB[7:0] TTL green signal channel
4,3,154,153,150-147 BB[7:0] TTL blue signal channel
GPIO Interface
87 GOUT1/PWM1 PWM output 1
86 GOUT0/PWM0 PWM output 0
2 BYPASS Outside connect filter capacitor
29 DDC_DAT Analog interface DDC data
30 DDC_CLK Analog interface DDC clock
31 DDCROM_CLK DDC ROM clock
32 DDCROM_DAT DDC ROM data
34 XIN Crystal oscillator signal input
35 XOUT Crystal oscillator signal output
Power Pins
48, 54, 58, 77 AVDD A/D convert power supply
56 AVDD_PLL PLL power supply
36 AVDD_MPLL MPLL power supply
10, 22, 88, 99, 111,
129, 139, 151 VDDP Digital signal output power supply
19, 102, 114, 142 VDDC Digital circuit power supply
1, 9, 20, 21, 37, 42,
45, 51, 57, 59, 76,
81, 89, 100, 101,
112, 113, 130, 140,
141, 152
GND Digital circuit ground

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MST518 Internal Diagram:
Model No.: LCT15CH12ST.doc
Version: 1.0

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Model No.: LCT15CH12ST.doc
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2. TDA15021H:
The third-generator super integrated circuit UOC III which designed by Philips company
recently integrates with video decode、2D comb filter、high quality audio transacting technique,
suitable with the European teletext technique and suitable with US closed caption and V-chip
function compatible with single series IC. The series of UOC III have high integrity, besides
completing the Processing of all small signal (IF signal demodulation, video decode, H/V
signal, sound DSP), and integrate all the MCU function. It has many Advantages, example: the
compact circuit、good performance、simple craft, etc. it matches with company’s high
performance price ratio and high product efficiency demanding. It is suitable for 4:3 or 16:9、
50/60HZ and A100/120HZ TV system, the main characteristic below:
zMulti-system IF demodulation、analog video decode
zComb filter internal
zNICAM、stereo auto identify and decode
zSCART input channel source auto identify(RGB、CVBS),SCART image input format
identify(4:3、16：9)
zSupport 4:3、16:9 display format
zTOP/FLOF TELETEXT（10 page）receive display
zChannel auto install ACI function（can preset）
z4 CVBS or 3 Y/C input,1 CVBS output,2 YcrCb/2 RGB input
z4 AV audio input,1 AV adjustable audio volume output
zVolume auto level control circuit
zGlobal FM demodulation
zPicture quality enhancement of dynamic peak value control、skin color correct、Gamma
correct、Black level extension etc.
zCan turn down horizon and vertical scan part，output H/V sync. signal to Scalar
z128K Flash Memory inside, support program on line
zAutomatic Y/C signal identify
TDA15021H Pin Function:
Pin Definition Pin Function
1 VSSP2 Grounding
2 VSSC4 Grounding
3 VDDC4 +1.8V
4 VDDA3 +3.3V
5 VREF_POS_LSL +3.3V
6 VREF_NEG_LSL+HPL 0V
7 VREF_POS_LSR+HPR +3.3V
8 VREF_NEG_HPL+HPR 0V
9 VREF_POS_HPR +3.3V
10 XTALIN Crystal oscillator input
11 XTALOUT Crystal oscillator output
12 VSSA1 Grounding
13 VGUARD/SWIO Protecting voltage input or I/O
14 DECDIG DECDIG signal input
15 VP1 +5V
16 PH2LF The second grade horizontal phase lock filter
17 PH1LF The first grade horizontal phase lock filter
18 GND1 Grounding
19 SECPLL SECAM PLL decouple
20 DECBG Inside reference voltage decouple
21 EWD/AVL VDD5A voltage input
22 VDRB TV vertical sync signal output

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23 VDRA vertical sync output
24 VIFIN1 VIF input 1
25 VIFIN2 VIF input 2
26 VSC Outside connect vertical ramp capacity
27 IREF Re-current input
28 GNDIF IF grounding
29 SIFIN1 SIF input 1
30 SIFIN2 SIF input 2
31 AGCOUT tuner RF AGC control voltage output
32 EHTO Over voltage protection input
33 SSIF MUTE control signal input
34 AUDIOIN5L Av left track signal input
35 AUDIOIN5R Av right track signal input
36 AUDOUTSL SCART/CINCH left track output
37 AUDOUTSR SCART/CINCH right track output
38 DECSDEM Track demodulator decouple
39 QSSO De-emphasis capacitor
40 GND2 grounding
41 PLLIF IF_PLL filter
42 SIFAGC Sound intermediate frequency auto gain control
43 IFVO IF demodulation video output
44 FMRO Fm broadcast output
45 VCC8V The supply voltage of Sound switch
46 AGC2SIF The second sound intermediate frequency auto
gain control
47 VP2 +5V
48 IFVO The video output of Choose channel
49 AUDIOIN4L HD signal left track audio output
50 AUDIOIN4R HD signal right track audio output
51 CVBS4/Y4 S-video luminance signal input
52 C4 S-video chroma signal input
53 AUDIOIN2L PC signal left track audio input
54 AUDIOIN2R PC signal right track audio input
55 CVBS2/Y2 AV CVBS signal input
56 AUDIOIN3L Inside DVD module left track audio input
57 AUDIOIN3R Inside DVD module right track audio input
58 CVBS3/Y3 Inside DVD module brightness signal input
59 C2/C3 Inside DVD module chroma signal input
60 AUDOUTLSL Main channel left track output
61 AUDOUTLSR Main channel right track output
62 AUDOUTHPL Earphone channel left track output
63 AUDOUTHPR Earphone channel right track output
64 CVBS/PIP CVBS/PIP output
65 SVM Scan modulate output
66 FBISO Fly back input/sandcastle output or composite H/V
timing output
67 HOUT Horizontal sync signal output
68 VSS comb Grounding
69 VDD comb +5V
70 VIN V signal input
71 UIN U signal input
72 YIN Y signal input
73 YSYNC Y signal input for Sync separate
74 YOUT Y signal output
75 UOUT U signal output
76 VOUT V signal output
77 INSSW3 RGB / YpbPr insert identify signal input

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78 R/PrIN3 R/Pr signal input
79 G/YIN3 G/Y signal input
80 B/PbIN3 B / Pb signal input
81 GND3 Grounding
82 VP3 +5V
83 BCLIN Beam current limiter input
84 BLKIN Black current input
85 RO R basic color signal input
86 GO G basic color signal output
87 BO B basic color signal output
88 VDD3 +3.3V
89 VREFAD_NEG 0V
90 VREFAD_POS +3.3V
91 VREFAD Audio ADC re voltage
92 GNDA Grounding
93 VDDA +1.8V
94 VDD3A +3.3V
95 VSSADC Grounding
96 VADC +1.8V
97 INT0 Remote control signal input
98 P10/INT1 DPF clock line
99 P11/T0 DPF data line
100 VDDC2 +1.8V
101 VSSC2 Grounding
102 P04/12SWS MST reset signal
103 P03/12SCLK HD,PC select control signal
104 P02/12SDO2 Power Amplifier standby control signal
105 P01/12SDO1 TV-DPF select control signal
106 P00/12SDII/O Turn on control signal
107 P13/T1 MST chip select signal
108 P16/SCL UOCI2C bus clock line
109 P17/SDA UOCI2C bus data line
110 VDDP +3.3V
111 P20/TPWM Red indicator light control signal
112 P21/PWM0 Green indicator light control signal
113 P22/PWM1 TFT power supply control signal
114 P23/PWM2 Inside DVD module power supply control signal
115 P30/ADC0 Reserve IO port
116 P31/ADC1 Earphone insert identify signal input
117 VDDC1 +1.8V
118 VDD18 +1.8V
119 P32/ADC2 DVD key-press signal input
120 P33/ADC3 TV key-press signal input
121 VSSC Grounding
122 P24/PWM3 Background control signal output
123 P25/PWM4 SAW filter control signal
124 VDDC3 +1.8V
125 VSSC3 Grounding
126 P12/INT2 MST interrupt signal input
127 P14/RX MST data line
128 P15/TX MST clock line

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TDA15021H Internal Block Diagram:
Model No.: LCT15CH12ST.doc
Version: 1.0

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3 TDA9178 :
TDA9178 is an analog signal processor with standard YUV input and output interface .It
provide three main process functions: luminance vector, color vector and spectrum
process. It can finish comprehensive picture improving function independently. The
characteristics of the TDA9178 are below:
zLuminance Transient Improvement (LTI), Colour Transient Improvement (CTI)
zVariable gamma control
zSelf-suitable black level extend control
zSkin color correction, green intensity ,blue extend
zNoise measurement and reduced noise process function
zLine Width Control (LWC)
TDA9178 PIN FUNCTION
Pin Definition Pin Function
1 Sandcastle input Sandcastle input
2 Not connected Grounding
3 ADC input 1 A/D converter input 1
4 ADC input 2 A/D converter input 2
5 ADC input 3 A/D converter input 3
6 Luminance input Y input
7 Address selection input I2C address choose input port
8 U signal input U input
9 V signal input V input
10 Test pin Grounding
11 Serial clock input (I2C-bus) I2C bus clock signal
12 Not connected Not connected
13 Not connected Not connected
14 Serial data input/output
(I2C-bus) I2C bus data signal
15 Decoupling digital supply Connect decouple capacitor external
16 V signal output V signal output
17 U signal output U signal output
18 Ground Ground
19 Luminance output Y signal input
20 Supply voltage Supply power
21 SCAVEM output Scan velocity modulate output
23 Not connected Grounding
24 Not connected Grounding

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DA9178 Internal Block Diagram:
Model No.: LCT15CH12ST.doc
Version: 1.0

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4 TDA1517AWT :
The TDA1517ATW is a double channel class-AB power amplifier contained in a plastic
heat sink thin shrink small outline package (HTSSOP20). The device is primarily
developed for multimedia applications.
a) Outside circuit is simple
b) Mute、standby is controllable
c) Temperature protect circuit
d) low noise switch
e) Constant gain
TDA1517 PIN FUNCTION:
Pin Definition Pin Function
3 Non-inverting input Audio input
5 Supply voltage ripple rejection Bias circuit filter
8、9 Output Audio output
12、13 N.C. Not connected
15、16 Supply voltage ＋12V power supply
17 Mode select switch Work mode select
18 Inverting input Reverse input terminal （connect capacitor to
ground ）
1、2、4、6、
7、10、11、
14、19、20
GND ground
TDA1517 Inner Block Diagram:
Model No.: LCT15CH12ST.doc
Version: 1.0