Akai LTA-32N658HCP User manual

LTA-32N658HCP
LTA-32N680HCP
LTC-26N680HCP
LTC-32N680HCP

LCD COLOUR TV
SERVICE MANUAL
MODEL:
LTC-26N680HCP
LTC-32N680HCP
LTA-32N680HCP
LTA-32N658HCP
CHASSIS NO.: LS02/PS02
1

Please read this manual carefully before service.
2

Catalog
UChapter1 Specifications and CompositionU......................................................4
UChapter2 Function Introduction of Main IC U....................................................7
UChapter3 Analysis of Signal process Flowchart and key point
measure dateU....................................................................................................31
UChapter4 Maintenance Procedure and Examples of Typical
troubleshootingU..............................................................................................40
UChapter5 Spare Part ListsU.............................................................................................42
UChapter6 Factory Setup and noticeU......................................................................43
Appendix: Circuit Schematic diagram
3

0BChapter 1: Specifications and Composition
1. Models for LS02/PS02 chassis :
Region Europe America Other regions
Original
Models
LT26GHxxE LT37GHxxE
LT32GHxxE LT42GHxxE
LT47GHxxE
xx:01,19,29,30,41 etc.
PT32GHxxE PT42GHxxE
PT50GHxxE
xx:218,528,26,18,36
LT26GHxxU LT37GHxxU
LT32GHxxU LT42GHxxU
LT47GHxxU
xx:01,19,29,30,41 etc.
PT32GHxxU PT42GHxxU
PT50GHxxU
xx:218,528,26,18,36
LT26GHxxA LT37GHxxA
LT32GHxxA LT42GHxxA
LT47GHxxA
xx:01,19,29,30,41 etc.
PT32GHxxA T42GHxxA
PT50GHxxA
xx:218,528,26,18,36
2. Main Feature
Region Europe America Other regions
Color system PAL、SECAM NTSC、PAL M/ N PAL、NTSC、SECAMRF
signal Sound system D/K、B/G、I、L/L’ M/N D/K、B/G、I、M
Video or Y/C signal PAL、NTSC、SECAM PAL、NTSC、SECAM PAL、NTSC、SECAM
Program presetting 100 （0-235）181 （AIR：2-69；CABLE：
1-125）236 （0-235）
Audio output（THD≤7%）5W+5W 5W+5W 5W+5W
Power source 100V～240V 100V～240V 100V～240V
Teletxt 100 pages X 100 pages
CCD X Yes X
VCHIP X Yes X
Sound demodulator NICAM、IGR BTSC NICAM、IGR
SCART Yes X X
VGA Yes Yes Yes
YPbPr Yes Yes Yes
HDMI Yes Yes Yes
Earphone Yes Yes Yes
OSD language
English, French,
German, Italian,
Portuguese etc.
English, French,
Portuguese, Spanish etc.
English, French, German,
Spanish etc.
Auto Off without Signal
Reception 5 minutes
Program booking 5 program booking. Turn to the corresponding program at the booking time.
Swap Customer could rearrange the channels according to personal habit
Plug and Play LCD TV could be used as computer screen, no need for the installation of
software, which is Plug and Play in real sense
3. Unit IC Compositions：
LCD TV with LS02/PS02 chassis is made up of switch power, system control circuit, video
processing circuit, audio processing circuit, Power Amplifier circuit, AV input circuit, LCD screen
module. Block circuit diagram is shown as below:
4

IF
Pb1
R3
SCART1
LVDSD_Port
CHN Model
LO1
EU Model
5V
TV-CVBS,SIF
Pb1
IR_Key
VGA
Lin2/Rin2 Lo2/R02
V1 R1 L2
Y1Pb1PR1/L3R3
8Mx16DDR
Speaker
Y C
19
L3
Pb1
R2
TUNER
SCART2
SVP_AX32
AMP
L1
I/O
Flash
1
R3
Y1 RO1
VO1
HDMI
Headphone
Pb1
RS232
PS301
Y1
V1,RGB,FS1,FB1,Vout1
V3
S-Video
Lin1/Rin1 Lo1/Ro1
Y1Pb1Pr1
E2PROM
Y2 Pb2 Pr2
V2
S_Video
Y C,FS2
S_Video
V3
L3
12V
5

4. Introduction of PCB module
LCD TV with LS02/PS02 Chassis is made up of power board, side AV board, remote
control reception board, key board, and mainboard. The table below is the introduction of the
function of all printed board modules.
No. Parts Description
1 Mainboard
module
Mainboard module is the core of LCD TV signal processing. Under the control
of the system control circuit, It undertakes the task of converting the external
input signal into the unified digital signal that the LCD screen could identify.
Mainboard controls the whole machine through IIC bus, decode VIDEO
signal, controls the Video (brightness, contrast, chroma, hue, definition etc),
white balance adjusts, generates OSD, de-interlaces signal, converts signal
frequency, and finishes signal A/D and D/A conversion, video enhancement,
LVDS signal coding and output; it has Scart , S-Video, AV , YPbPr, HDMI and
PC interface, Tuner input, sound demodulation, sound processing, sound
power amplifier, and online update.
2
Remote
reception
module
The remote reception board module is constituted by an indicator-light and a
remote reception. Customer could manipulate the LCD TV by using remote
controller very conveniently. By the color of the indicator light, the operation
mode of the LCD TV could be judged (red is standby, green is power on).
3 Built-in powe
r
Convert the 100V～240V （50/60HZ）AC into DC, output have +12V, +5V,
+3.3V and the +5V_STB in standby state.board module
4 Keyboard
module
Keyboard module has 7 function keys (program +/-, volume +/-, AV/TV,
menu ,power), customer could use the key to operate the TV freely.
5 LCD screen
module
LCD screen has built-in inverter that convert DC into high voltage AC signal to
turn on the backlight CCFL (Cold Cathode Fluorescent Light); the LCD screen
process the video signal from signal board and reappear.
6 Side AV
board Side AV board is used for earphone output.
6

Chapter 2: Function Introduction of Main IC
1. Main ICs and functional modules of LS02/PS02 chassis
No. Item no. Model Main function
1 U8
AFT7/W003
AFT7/W103
AFT7/W300
Tuner,output sound IF and video signal
2 U1 SVP-AX32LF/SVP-AX68LF
SVP AX family video processors provide the
highest performance, target the converging
HDTV-ready and PC-ready LCD TV, PDP TV
applications where high precession processing of
video, which Embed in ADC converter、3D comb
filter 、HDMI processor、video decoder 、LVDS
transmitter etc.
3 U3 AT24C64-SO8-DNS EEPROM
4 U5 W25X80-VSSIG 8M-bit Serial Flash, Store the Control program.
5 U7 HY5DU281622FTP-4 8M×16bits DDR SDRAM
6 U9 TDA9886T Multistandard alignment-free IF-PLL demodulators
7 U11 74HC4052 Audio signal switch of AV terminal
8 U15 74LVC14A VGA line and field synchronizing signal waveform
shaping
9 U16 AT24C64 EEPROM
10 U17 IRF7404/AO4459 Field Effect Transistor
11 U22 MP1411DH DC-DC converter
12 U20、U24 AP1117E33 LDO,5V to 3.3V DC converter
13 U23 AP1122EL LDO,5V to 1.2V DC converter
14 U27 TDA7266SA Audio amplifier (BTL output)
15 U32 PS201 HDMI two-to-one switch
1B2. Function introduction of ICs or functional module of LCD TV with LS02/PS02
chassis
1. Tuner (Asian TV:AFT7/W003;European TV: AFT7/W103;American TV: AFT7/W300)
No. Terminal name Description
1 AGC AGC voltage supply
2 NC No Connected
3 SAS Address Selection Line
4 SCL Serial Clock Line
5 SDA Serial Data Line
6 NC No Connected
7

7 BP +B For PLL & Mixer
8 ADC/NC ADC Input/ No Connected
9 NC No Connected
10 NC No Connected
11 IF1 IF Output
12 ANT VHF/UHF Signal Input
2. Video processing IC SVP-AX32LF/SVP-AX68LF
The SVPTMCX video processor is a highly integrated system-on-a-chip device, targeting the
converging HDTV-ready and PC-ready LCD TV, PDP TV applications where high precision
processing of video and data are the requirements. SVPTMCX contains 6th generation
dual-purposed triple 10-bit high-precision and high speed video ADCs for both PC and video
inputs, the high-performance multi-format 3D digital comb video decoder that supports NTSC,
PAL, and SECAM*, a HDTV sync separator, motion adaptive de-interlacing engine, and the
video format conversion engine, supporting multi-window display in many different output
modes. Trident’s DCReTM – Digital Cinema Reality engine, is integrated inside the SVPTMCX
family to provide the most natural cinema-realistic images. The DCReTM technology integrates
advanced 3D-comb video decoding, advanced motion adaptive de-interlacing, object-based
digital noise reduction, advanced 7th generation scaler, film mode support, average picture
level (APL), edge smoothing and dynamic sharpness enhancement. Trident's patented Unified
Memory Architecture (UMA) that allows frame rate conversion, 3D comb video decoding, and
video enhancement processing to share the same memory buffer that is made up of high-speed
and cost-effective PC graphic memory. All these advanced digital processing techniques
combined with a true 10-bit video data processing for the most optimal video fidelity to provide
the most natural and cinema quality video images. Designed for maximum system design
flexibility, SVPTMCX integrates all video interfaces to support converging digital video, analog
video, and PC data applications. The users of Trident's single chip SVP™CX series video
processor(s) will benefit from many features while maintaining a price competitive advantage
over the existing solution(s)
Main features:
●Integrated 7th Generation Motion and Edge Adaptive De-interlacing
●Integrated ADC
●PC auto tune
●Built-in 8-bit LVDS Transmitter
●Advanced 7th generation cubic-4 image scaling engine
●Advanced Chroma Processing and Dynamic Contrast Function
●Green color stretch, blue color stretch, skin color enhancement
●Integrated 7th Generation Motion Adaptive 3D Digital Comb Video Decoder with
Programmable Filter
●60Hz～100Hz interlaced scanning and 50Hz～75Hz progressive scanning
●frame rate conversion
●14D：dynamic picture enhancements
●Advanced Film Mode Recovery-3:2/2:2 pull down
●Build-in A/D conversion function
8

●Teletext function
●Supports 16bits DDR memory interface
●Multi-screen display mode
●OSD and VBI/Closed caption and advanced OSD engine
Pin function description:
Table1: Pin Assignments for CPU-related and GPIO pins
9