36447879 ak30 tv dvd divx sm vestel

Download 36447879 Ak30 Tv Dvd Divx Sm Vestel

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  • 1CONTENTS

    A. ANALOG PARTSAFETY PRECAUTIONS: ........................................................................................................................................... 3

    TV set switched off ...................................................................................................................3 Measurements ...........................................................................................................................3

    PERI-TV SOCKET ........................................................................................................................................................3 SCART 1 ..................................................................................................................................3 SCART 2 ..................................................................................................................................3

    1. INTRODUCTION ......................................................................................................................................................4 2. SMALL SIGNAL PART WITH STV2248 .........................................................................4 2.1 Vision IF amplifier..............................................................................................................4 2.2 QSS Sound circuit (QSS versions) .....................................................................................4 2.3 FM demodulator and audio amplifier (mono versions) ......................................................4 2.4 Video switching ..................................................................................................................5 2.5 Synchronisation circuit .......................................................................................................5 2.6 Chroma and luminance processing .....................................................................................5 2.7 RGB output circuit ..............................................................................................................6 2.8 -Controller ........................................................................................................................7

    3. TUNER ........................................................................................................................................................................74- DIGITAL TV SOUND PROCESSOR MSP34X0....................................................................................................85. SOUND OUTPUT STAGE TDA7266L/TDA7266 ...................................................................................................86. VERTICAL OUTPUT STAGE WITH TDA8174A .................................................................................................87. TRIPLE VIDEO OUTPUT AMPLIFIER TDA6107JF ..........................................................................................88. POWER SUPPLY (SMPS) ........................................................................................................................................89. POWER FACTOR CORRECTION .........................................................................................................................810. POWER CARD 11PW04-3, 11PW05..811. RGB SWITCHING CARD 11RGB30-3......912. SERIAL ACCESS CMOS 8K EEPROM 24C08 ...................................................................................................913. CLASS AB STEREO HEADPHONE DRIVER TDA1308 ................................................................................... 914. SAW FILTERS .........................................................................................................................................................915. IC DESCRIPTIONS AND INTERNAL BLOCK DIAGRAM ............................................................................. 9

    ST92195................................................................................................................................10 STV224X ..............................................................................................................................11 UV1315, UV1316, UV1336 ,TECC2949PG40B,TAEA-G0XXD ,ChongQing QingJia .....12

    TDA7266/TDA7266L ..........................................................................................................14 TDA8174 ..............................................................................................................................15 TDA6107JF ..........................................................................................................................15 MC44608 ..............................................................................................................................16 MSP34X0G ..........................................................................................................................17 24C08....................................................................................................................................18 TDA1308 ..............................................................................................................................19 PI5V330.20 SAW FILTERS.....................................................................................................................21

    SERVICE MENU ADJUSTMENTS...........................................................................................................................21OPTIONS ......................................................................................................................................................................31GENERAL BLOCK DIAGRAM of 11AK30 ............................................................................................................. 37CIRCUIT DIAGRAMS................................................................................................................................................38

  • 2DO NOT CHANGE ANY MODULE UNLESS THE SET IS SWITCHED OFFThe mains supply part of the switch mode power supplys transformer is live.Use an isolating transformer.The receiver complies with the safety requirements.

    SAFETY PRECAUTIONS:The service of this TV set must be carried out by qualified persons only. Components

    marked with the warning symbol on the circuit diagram are critical for safety and must only bereplaced with an identical component.- Power resistor and fused resistors must be mounted in an identical manner to the originalcomponent.- When servicing this TV, check that the EHT does not exceed 26kV.TV set switched off:Make short-circuit between HV-CRT clip and CRT ground layer.Short C809 before changing IC800 and IC801 or other components in primary side of the SMPSpart.

    Measurements:Voltage readings and oscilloscope traces are measured under the following conditions:Antenna signals level is 60dB at the color bar pattern from the TV pattern generator. (100% white,75% color saturation)Brightness, contrast, and color are adjusted for normal picture performance.Mains supply, 220VAC, 50Hz.

    PERI-TV SOCKET

    - The figure of PERI-TV socket-

    SCART 1 PINING

    1 Audio right output 0.5Vrms / 1K2 Audio right input 0.5Vrms / 10K3 Audio left output 0.5Vrms / 1K4 Ground AF5 Ground Blue6 Audio left input 0.5Vrms / 10K7 Blue input 0.7Vpp / 75ohm8 AV switching input 0-12VDC /10K9 Ground Green10 -11 Green input 0.7Vpp / 75ohm12 -13 Ground Red14 Ground Blanking15 Red input 0.7Vpp / 75ohm16 Blanking input 0-0.4VDC, 1-3VDC / 75 Ohm17 Ground CVBS output18 Ground CVBS input

    19 CVBS output 1Vpp / 75ohm20 CVBS input 1Vpp / 75ohm21 Ground

    SCART 2 PINING

    1 Audio right output 0.5Vrms / 1K2 Audio right input 0.5Vrms / 10K3 Audio left output 0.5Vrms / 1K4 Ground AF5 Ground Blue6 Audio left input 0.5Vrms / 10K7 Blue input8 AV switching input 0-12VDC /10K9 Ground Green10 -11 -12 -13 Ground Red14 Ground Blanking

  • 315 -16 -17 Ground CVBS output18 Ground CVBS input

    19 CVBS output 1Vpp / 75ohm20 CVBS input 1Vpp / 75ohm21 Ground

    1. INTRODUCTION11AK30 is a 90 chassis capable of driving 20/21 tubes at the appropriate currents. The chassisis capable of operating in PAL, SECAM and NTSC standards. The sound system is capable ofgiving 5 watts RMS output into a load of 8 ohms. One page, 7 page SIMPLETEXT, TOPTEXT,FASTTEXT and US Closed Caption is also provided. The chassis is equipped with a double-deck42 pin Scart connector.

    2. SMALL SIGNAL PART WITH STV2248:STV2248 video processor is essential for realizing all small signal functions for a color TVreceiver.2.1 Vision IF amplifier3The vision IF amplifier can demodulate signals with positive and negative modulation. The PLLdemodulator is completely alignment-free. Although the VCO (Toko-coil) of the PLL circuit isexternal, yet the frequency is fixed to the required value by the original manufacturer thus theToko-coil does not need to be adjusted manually. The setting of the various frequencies (38.9 or45.75 MHz) can be made via changing the coil itself.

    2.2 QSS Sound circuit (QSS versions)The sound IF amplifier is similar to the vision IF amplifier and has an external AGC de-couplingcapacitor. The single reference QSS mixer is realised by a multiplier. In this multiplier the SIFsignal is converted to the inter-carrier frequency by mixing it with the regenerated picture carrierfrom the VCO. The mixer output signal is supplied to the output via a high-pass filter forattenuation of the residual video signals. With this system a high performance hi-fi stereo soundprocessing can be achieved. The AM sound demodulator is realised by a multiplier. The modulatedsound IF signal is multiplied in phase with the limited SIF signal. The demodulator output signal issupplied to the output via a low-pass filter for attenuation of the carrier harmonics. The AM signalis supplied to the output via

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