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BBK LT2002S Service Manual

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Summary of Contents for BBK LT2002S

  • Page 1 LT2002S ser vice manual...
  • Page 2 Catalog Chapter One About Maintenance 1.1 Safety precautions 1.1.1 Power supply 1.1.2 Precautions for antistatic 1.1.3 Precautions for display screen 1.1.4 About placement position 1.2 Maintenance method 1.2.1 Visualized method 1.2.2 Electric resistance method 1.2.3 Voltage method 1.2.4 Current method 1.2.5 Cutting method 1.2.6 Element substitution method 1.2.7 Comparison method...
  • Page 3 Chapter Three Principle and Servicing Section One Principle of the Player 3.1.1 Introduction to the player 3.1.2 Introduction to IC used by the player 3.1.3 Block diagram of the player Section Two Unit Circuit Principle 3.2.1 System control circuit 1. System reset circuit 2.
  • Page 4 Section Five Function Introduction to IC 3.5. 1 function introduction to STV8216 3.5. 2 function introduction to MST518 3.5. 3 function introduction to Mp1430 3.5. 4 function introduction to W79E632 3.5. 5 function introduction to TVP5146 3.5. 6 function introduction to NCP1377 3.5.

  • Page 5: Chapter One About Maintenance

    Chapter One About Maintenance 1.1 Safety precautions 1.1.1 Power supply When maintenance personnel are repairing DVD TV, he should pay special attention to the power with 220V 800V AC and 330V DC which will cause hurt and damage to persons! 1.1.2 Precautions for antistatic Movement and friction will both bring static electricity which causes serious damages to integrated IC.

  • Page 6: Maintenance Method

    1.1.4 About placement position 1. Never place TV in positions with high temperature and humidity. 2. Avoid placing near high magnetic fields, such as loudspeaker or magnet. 3. Positions for placement should be stable and secure. 1.2 Maintenance method 1.2.1 Visualized method Directly view whether abnormalities of collision, lack of element, joint welding, shedding welding, rosin joint, copper foil turning up, lead wire disconnection and elements burning up among pins of Elements appear.

  • Page 7: Element Substitution Method

    1.2.6 Element substitution method When some elements cannot be judged good or bad, substitution method may de adopted directly. 1.2.7 Comparison method A same good PC board is usually used to test the correct voltage and waveform. Compared these data with those tested through fault PC board, the cause of troubles may be found. Through the above maintenance method, theoretical knowledge and maintenance experience, all difficulties and troubles will be readily solved.

  • Page 8: Chapter Two Operation Instructions

    Chapter Two Operation Instructions 2.1 LOCATION AND FUNCTION OF CONTROLS 2.1.1 Remote Controller STANDBY MUTE STANDBY To switch the unit between standby mode and power on mode. NUMBER BUTTONS To directly select program number. TWO-DIGIT NUMBER BUTTON To switch one or two-digit program number. -/-- SOURCE S-VIDEO...

  • Page 9: Panel Control

    2.1.2 Panel Control This TFT-LCD TV allows you to easily adjust the characteristics of the image being displayed. All of these adjustments are made by using the control buttons on the top of the TV. Front cartouche SOURCE SETUP Key cover board There are 7 keys for user`s control including POWER, SOURCE, SETUP , CH-,CH+, VOL- and VOL+.
  • Page 10 TV SETUP This product can store up to 100-channel programs (0 99). You can select your favorite channel through [CH+/-] or number buttons, and you can scan and store all of the channels through manual or automatic mode. In TV mode, press [SETUP] button on the remote control or [SETUP] key on the control panel, the menu will show as follows: # Through pressing [ ] button on the remote control, you can select main menu sections(main...
  • Page 11 2 . 3 . 2 S O U N D Select " "and menu will show as follows: SOUND SOUND USER BALANCE BASS TREBLE SELECT ENTER RETURN SETUP Press [ ] button to select item and press [ ] button to adjust . The following is sound item description.
  • Page 12 NOTE During the searching, you can press [SETUP] button to stop. CHANNEL EDIT CHANNEL SKIP SWAP CONFIRM Description Item To select current channel here. CHANNEL To select "Yes " or "No ", you can select "Yes " to make current channel unaccessible while using SKIP [CH+/-] button to browse channels.

  • Page 13: Video Setting Menu

    # SECAM system is only used by some European countries and districts, such as France. # If the local system is SECAM L, the color system must be selected as "SECAM" and sound system must be selected as "L". 2.3.5 NICAM/BILINGUAL RECEIVING If you can receive Nicam/bilingual signal, you can operate as follows to enjoy that.

  • Page 14: Checking Accessories

    2.5 20.1” TV SPECIFICATION 2.6 CHECKING ACCESSORIES Remote Controller Power Cord Operational Manual Batteries(AAAX2) - 10 -...

  • Page 15: Introduction To Ic Used By The Player

    Chapter Three Principle and Servicing Section One Principle of the Player 3.1.1 Introduction to the player Electronic scheme of LT2002S adopts LCD components (LC201V02-SDB1 20" )+inverter components (INV607)+MST518VA+TVP5146M1+STV8216+TDA7266P+tuner JS-6B2/121+CPU (W79E632A40PN ), which support PAL BG/DK/I SECAM BG/DK/L/L RF signal modulating, PAL/NTSC/SECAM/PAL60 multi-system video signals, BG/DK/I/LL/L accompanying system’s FM,...
  • Page 16 Speaker_L AUDIO_R_AMP LOUT+ LOUT AUDIO_L_AMP Tuner MONOIN Audio amplifying circuit U11 TDA7266P EXT_IN_R 27MHZ Multi-channel audio Speaker_R EXT_IN_L ROUT+ MUTE selection Mute control circuit AUDIO_OUT_R ROUT- Q6/Q5 NICAM signal AUDIO_OUT_L 8216_RST terminal processing U9 STV8216 AMP_MUTE 14.318MHZ AMP_STBY SCART_OUT_R AMP_STB SCART_OUT_L control circuit SCART_IN_R...

  • Page 17: System Control Circuit

    Section Two Unit Circuit Principle 3.2.1 System control circuit System control circuit is mainly composed of reset circuit, clock circuit and W79E632. W79E632 is responsible for the control and coordination of the player’s system; W79E632 is a programmable MCU processor; function of each I/O port is adjusted through software and can support the upgrading of external upgrading device.
  • Page 18 2. System clock circuit (1) System clock circuit is shown in the figure 3.2.1.2: W79E632X440PX Figure 3.2.1.2 System clock circuit (2) Working principle: this clock circuit is mainly composed of X4, C148 and C155, in which X4 is a 22.1184MHZ crystal oscillator; C148 and C155 are externally-connected resonance capacitors to produce a 22.1184MHZ clock signal to provide for W79E632 to generate clock signal required by system through internal doubling circuit to act as working clock.
  • Page 19 (2) Working principle Working process from power-on to standby: after power on, 12V power outputted by power board outputs a group of +5V power (marked as +5VEXT in schematic diagram) through being voltage stabilized by U14 , during which time power supply of +5VEXT and +12V is normal. +5VEXT is mainly supplied to W79E632, MST518 and each control circuit.

  • Page 20: Audio Circuit

    (2) Working principle: IIC bus is a kind of simple, dual-direction and synchronous serial line developed by PHILIPS company. Only 2 lines (serial clock line and serial data line) are required to connect between components on bus to transmit information. This bus is high-performanceserial bua which has function of decision and synchrony of high and low speed devices required by multi-player System with wide application range.
  • Page 21 Tuner LOUT+ MONOIN AUDIO_R_AMP Speaker_L EXT_IN_R EXT_IN_L LOUT Audio/video AUDIO_OUT_R Multi-channel audio TDA7266P terminal selection AUDIO_OUT_L Audio NICAM signal amplifying processing SCART_OUT_R circuit U9 STV8216 SCART_OUT_L ROUT+ AUDIO_L_AMP SCART_IN_R SCART Speaker_R SCART_IN_L ROUT- Figure 3.2.2.1 Audio processing circuit block diagram 1.
  • Page 22 (3) Working principle: when tuner receives NICAM signal, it outputs from pin 11 of tuner (SIF), and inputs into pin 73 of STV8216 through the filtering circuit composed of C99, C98 and L24 components and then restores to audio signal through being modulated by internal circuit of STV8216 and sends to audio amplifying circuit through pin 28, 29 of STV8216.

  • Page 23: Mute Circuit

    By internal dual-bridge audio amplifier to drive loudspeaker to make sounds. This IC adopts +10V power supply, D15/D18/D19 is drop diode and pin 11 is standby control pin. After machine enters power-on state, pin 30 of W79E632 (AMP_STB) outputs high level and this IC enters working mode. 4.

  • Page 24: Video Circuit

    3.2.3 Video circuit Video circuit is mainly responsible for the input of external video signals, the processing of video signals send from tuner, and the drive processing of LCD screen, including video input selection, video A/D conversion circuit, LCD picture processing circuit and video output circuit. Video circuit block diagram is shown in the figure 3.2.3.1: TUNER_CVBS 14.318MH...

  • Page 25: Input Circuit

    Format change system, OSD generator, output clock producer and multi-format output display jack (support TTL, LVDS, RSDS). This player adopts digital signal input, which inputs from pin 91~98 of MST518VA, meanwhile TVP5146 also provides a 27MHZ clock signal to MST518VA. W79E632 performs data exchange and control to MST518VA through bus.

  • Page 26: Tuner Circuit

    Signal Signal Name Function description Name Function description direction direction A(B)OUT Audio right channel input Network communic ation data line 2 A(B)IN Audio right channel output RETURN Pr signal ground A(A)OUT Audio left channel input RETURN Blanking signal ground A-COM Audio signal ground RED I/O Pr signalI/O port...

  • Page 27: Power Supply Circuit

    (3) Tuner pin function is shown in the following table: Name Function Name Function (+)5V power supply pin SCLis connected with MCU NICAM jack SDA is connected with MCU TUNER_CVBS Video output 5V power is c onnect ed externally AUDIO Audio output 3.2.5 Power circuit Power circuit provides each function module with stable working voltage to ensure the normal...
  • Page 28 Value is 1.4 times of electric power, equal to 300V). For C1 performs filtering, 300V power is divided into two paths: one path is provided for switch module (U1_2/U1_3) through dropping voltage by R3~R7; and the other path reaches power pin of switch module (U1_7) through the winding of transformer to make transformer perform the storage and discharge of energy through the internal switch pipe.
  • Page 29 To voltage inputted to the feedback pin L1 of mp1048; AC circuit inputted by LI, through being sampled by circuit inside IC, switches to RMS voltage value and inputs to the reverse input end of internal amplifier to control the TH/TL of PWM signal. 5) Protection circuit: over-voltage/open-circuit protection is to fulfil the control of voltage feedback loop through sampling output voltage, connected in series by high voltage capacitor of 3KV/10PF and capacitor of 103/25V, composing voltage division circuit to switch output high voltage to voltage...

  • Page 30: Power Control Circuit

    (2) Working principle: Mp1430 is a voltage-drop style voltage stabilizing circuit. 12V power inputted by power supply circuit, through being voltage stabilized by Mp1430, outputs 5VEXT power directly supplied to load circuit, in which pin 5 of Ma1430 is feedback input pin and its reference voltage is 1.22V. When 5V power becomes high for certain reason, voltage of feedback end pin 5 also becomes high and control circuit inside Mp1430 will make output voltage of pin 3 of Mp1430 becomes low.
  • Page 31 5. Boost control circuit (1) Boost control circuit diagram is shown in the figure 3.2.5.5: Figure 3.2.5.5 Boost board control circuit (2) Working principle: after power on, +12V power is normal, machine is in standby state , ON/OFF_JINVERTER pin of MCU outputs high level, Q1 is saturated on, pin 4 of CN4 is low level and boost circuit stops working.
  • Page 32 (2) Boost circuit block diagram is shown in the figure 3.2.5.6: Brightness Full bridge control circuit Boost circuit Mp1048 High voltage output transformer Over-voltage/ terminal light lamp open-circuit protection T1~T6 CN2~CN7 Current control short-circuit protection FB1~FB6 LV1~LV6 Figure 3.2.5.6 Boost circuit block diagram (3) Working principle 1) Full bridge circuit: full bridge drive circuit is driven by mps1048 directly and full bridge is composed by 4 Nmos tubes (Q1A, Q1B, Q2A, Q2B).
  • Page 33 Voltage sampling, through being rectified by D2~D4, sent to voltage feedback pin LV of IC. When voltage sampled is over 1.2V, IC enters protection state to turn off pulse drive. 5) Other control circuit: pin 13 of MP1048 is the enable control end of this IC. When this pin is high level, IC enters working state.

  • Page 34: Section Three Servicing Cases

    Section Three Servicing Cases 3.3.1 Servicing cases [ Example 1 ] Symptom: black screen when power-on (background light of screen is not on) Description: from standby to power-on, screen is black all the time and panel indicator light can display normally. Analysis and troubleshooting: according to servicing experience, if screen is black when power-on, firstly place the head of oscillograph near high voltage of boost board and find that oscillograph has no inductive waveform, so we can make sure that boost board has not outputted high voltage.
  • Page 35 Analysis and troubleshooting: when this kind of trouble appears, firstly check whether power board has +12V voltage output. Test Cn6 flat cable holder and find that there is +12 voltage to video main board, which means that power circuit is ok; then check power control circuit and check whether pin 2 of U14 has input voltage and whether pin 3 has +5V voltage and result is normal.
  • Page 36 should be in indicator light control circuit. In standby, test emitter electrode of Q9 and it is high level and that of Q11 is low level, so we doubt that triode Q11is not on. After changing it, trouble is removed. Example 5 Symptom: noise appears when power on Description: press POWER button on remote control or control board to power on and off on each input mode and you may hear “pop”...
  • Page 37 Audio signal input. Check carefully and find that pin 28, 29 of U9 may probably have rosin joint. Use iron and tin to process and trouble disappears after power on again. Example 7 Symptom: remote control has no function Description: when pressing buttons on remote control, TV screen has no response. Analysis and troubleshooting: test voltage of 5V-IR pin of Cn7 and it is +4.96, which is normal.

  • Page 38: Troubleshooting Flowchart

    3.3.2 Troubleshooting flow chart [ Flow chart 1 ] Symptom: player not power on Description: switch on power, indicator light is not on and buttons have no function. Player not power on Whether pin 1 of main board socket Cn6 has 12V voltage Disconnect Whether...
  • Page 39 [ Flow chart 2 ] Symptom: power not on Description: no response after switching on player Power not on Check whether power board Check according to JP1 socket has troubleshooting process for 12V voltage “player not switch on” Check whether 12v Check whether output loop resistor to ground has short circuit...
  • Page 40 [ Flow chart 3 ] Symptom: no sound Description: there is image, but no audio output No sound No sound when watching TV; input source has firstly check whether pin 78 Change STV8216 no sound output of STV8216 has no audio signal input Check...
  • Page 41 [ Flow chart 4 ] Symptom: white screen Description: screen is white and indicator on White screen Check Check Check whether U15_37 whether L8 voltage is whether U2_4 pin is Change W79E632 (PANEL_ON) is low normal low level level Check Check whether 1.8V Check Q4 and peripheral...
  • Page 42 [ Flwo chart 5 ] Symptom: black screen Description: screen is black and indicator light is on. Black screen After power on, whether Check +5VEXT power other circuit working supply loop is normal Whether Change U15 U15_16 pin outputs low level Check whether CN4 pin 6 Check 12V power supply...
  • Page 43 [ Flow chart 6 ] Symptom: external input has no image Description: external input has no image but has sound. External input has no image Check according to Whether troubleshooting process for all external input has “a certain video terminal has no image no input”.
  • Page 44 [ Flow chart 7 ] Symptom: TV cannot search channels Description: channel cannot be searched T V cannot search channels Check whether tuner Check whether tuner power and TV signal have input has TUNER_CVBS signal output and then change tuner Check 1.
  • Page 45 [ Flow chart 8 ] Symptom: external output mode has no video Description: external output mode has no video but has audio. External output mode has no video Check Check according to troubleshooting whether input is process for “terminal has no input” normal Check whether LA7952...
  • Page 46 [ Flow chart 9 ] Symptom: input mode has no video input Description: input mode has no video input but has audio input. Input mode has no video input Test Test whether resistance to whether terminal has ground of terminal is 75-ohm signal input and change terminal Test...
  • Page 47 [ Flow chart 10 ] symptom: NICAM has no function Description: NICAM has no function and cannot be realized NICAM has no function Check Check whether clock frequency whether STV8216SIF Change tuner signal is is normal normal Check the circuit between tuner SIF signal and STV8216 Check Check crystal oscillator...
  • Page 48 [ Flow chart 11 ] Symptom: screen image flickers Description: screen image flickers and sound is normal Screen image flickers Check whether screen Check whether software flickers under other version is correct signal source Judge whether it is the Check whether display screen back ground light that flat cable contact is good flashes...
  • Page 49 [ Flow chart 12 ] Symptom: colour has distortion Description: picture colour has distortion Colour has distortion Check whether the 8-channel Change chip digital signal output of TVP5146 is normal Check Check whether 24-bit whether clock RGB output signal of MST518 Check X2/C92/C101 frequency is is normal...

  • Page 50: Waveform Diagram

    Section Four Waveform diagram This section collects signal waveform diagram of audio, video and each unit circuit with the purpose to help servicing personnel to judge where trouble lies in accurately and quickly to improve servicing skills. For the difference of oscillograph's type, model and tuner, a certain difference may exist, so the servicing personnel are expected to pay more attention to check in daily operation.
  • Page 51 3. X4-5.08V: waveform diagram when X4 is in standby (frequency 22.1184MHZ) 4. X3-3.44V: waveform diagram when X3 is working (frequency 27MHZ) 5. X2-3.3V: waveform diagram when X2 is working (frequency 14.318MHZ) - 47 -...
  • Page 52 6. X1-1.6V: waveform diagram when X1 is working (frequency 14.318MHZ) 7. U3_16: video signal waveform diagram of U3_16 pin when machine is receiving standard signal source in TV state. 8. U13_6: waveform diagram of SCL in IIC bus - 48 -...
  • Page 53 9. U13_5: waveform diagram of SDA in IIC bus 10. TVP5146_40: waveform diagram of TVP5146_40 pin outputting clock signal to MST518 (frequency 27MHZ) 11. TEK0013: waveform diagram of video signal outputted by U1_1 pin when machine is receiving standard signal source in TV state - 49 -...
  • Page 54 12. T1_14: waveform diagram of audio output pin of tuner when machine is receiving standard signal source in TV state. 13. T1_12: waveform diagram of video signal outputted by pin 12 of tuner when machine is receiving TV signal in TV state 14.
  • Page 55 15. RP5: waveform diagram of digital video signal outputted by TVP5146 (test point RP5) 16. ROUT: audio output waveform diagram (test point CN5) 17. R25: waveform diagram of H_SYNC signal outputted by MST518 (test point R25) - 51 -...
  • Page 56 18. R24: waveform diagram of Y_SYNC signal outputted by MST518 (test point R24) 19. R23: waveform diagram of DCLK signal outputted by MST518 (test point R23) 20. R22: waveform diagram of LDE signal outputted by MST518 (test point R22) - 52 -...
  • Page 57 21. PANEL_ON: waveform comparison diagram of POWER and PANEL_ON signal when machine enters power-on from standby 22. MST518_RP1: waveform diagram of drive signal outputted by MST518 23. INVERTER: waveform comparison diagram of POWER and ON/OFF_INVERTER signal when machine enters power-on from standby - 53 -...
  • Page 58 24. AMP_STB: waveform comparison diagram of AMP_STB and MUTE signal when machine enters power-on from standby 25. 8216_78: waveform diagram of audio signal from tuner when machine is receiving standard signal source in TV state (test point STV8216_78) 26. 8216_28: waveform diagram of audio signals from tuner that output from pin 28/29 after being processed by STV8216 when machine is receiving standard signal source in TV state - 54 -...
  • Page 59 27. 8216_18: waveform diagram of audio signals from tuner that output from pin 18/19 after being processed by STV8216 when machine is receiving standard signal source in TV state 28. 8216_1: waveform diagram of audio signals from tuner that output from pin 1/2 after being processed by STV8216 when machine is receiving standard signal source in TV state 29.
  • Page 60 30. Pin 38 RST: waveform comparison diagram of reset signal outputted by pin 38 of W79E632 (8216_RST) and POWER pin 31. Pin 30 MUTE: waveform comparison diagram of audio signal outputted by pin 30 of W79E632 (MUTE) and POWER pin - 56 -...
  • Page 61 Section Five Function Introduction to IC 3.5.1 function introduction to STV8216 1. Description TV Sound Demodulator: provides all the necessary circuitry for the demodulation of audio transmissions of European and Asian terrestrial TV broadcasts. The various transmission standards are automatically detected and demodulated without user intervention.

  • Page 62: Pin Definitions

    # Single and standard 27 MHz Crystal Oscillator # Embedded 3.3 V Regulators # Power supplies: 3.3 V Digital, 5 V or 8 V Analog # I = Input # O = Output # OD = Open Drain # B = Bidirectional # A = Analog # AP = Analog Power Supply # DP = Digital Power Supply...
  • Page 63 AI3L Left SCART3 Audio Input AI3R Right SCART3 Audio Input Not Used BGAP Bandgap Voltage Source Decoupling Not Used Left Loudspeaker Output Right Loudspeaker Output Subwoofer Output Left Headphone Output Right Headphone Output GNDSA Substrate Analog/Digital Shield Not Used Headphone Detection Input (Active Low) Hardware I²...
  • Page 64 GND2 0 V Power Supply for Digital Core, DSPs & IO Cells VDD2 3.3 V Power Supply for Digital Core, DSPs & IO Cells CKTST Must be Connected to 0 V Not Used Not Used I² S Bus Data Output ST/SDI Stereo Detection Output / I²...
  • Page 65 capability for green-mode requirements and spread-spectrum support for EMI management. 2. Feature # High-quality zoom and shrink scaling engine (Compatible with VGA thru SXGA) # Integrated 8-bit triple-ADC/PLL # On-screen display controller (OSD) # Supports dual-RGB inputs # Supports sRGB # Supports composite sync and SOG separator # Programmable 10-bit gamma correction # Integrated brightness &...
  • Page 66 REXT External resistor 390 ohm to AVDD BIN1 Analog Input Analog Blue Input from Channel 1 BIN1M Analog Input Reference Ground for Analog Blue Input from Channel 1 SOGIN1 Analog Input Sync-On-Green Input from Channel 1 GIN1 Analog Input Analog Green Input from Channel 1 GIN1M Analog Input Reference Ground for Analog Green Input from Channel 1...
  • Page 67 153, 150-147 126, GPO[6:0] Output w/ Pull-down Resistor TCON GPO[6:0]; 4~12mA driving strength programmable 155-160 OINV Output w/ Pull-down Resistor TCON “ Odd” Channel Inversion; 4~12mA driving strength programmable TCON “ Even” Channel Inversion; 4~12mA driving strength EINV Output w/ Pull-down Resistor programmable TCON “...
  • Page 68 “ Odd” Channel A-Link Negative RSDS Differential Clock Output from CLKAN Output “ Odd” Channel CLKBP Output B-Link Positive RSDS Differential Clock Output from “ Even” Channel CLKBN Output B-Link Negative RSDS Differential Clock Output from “ Even” Channel 109, 107, BA[3:0]P Output A-Link Positive RSDS Differential Data Output from “...
  • Page 69 GOUT1/PWM0 Output GOUT0/PWM0; 4mA driving strength Misc. Interface BYPASS For External Bypass Capacitor DDC_DAT I/O w/ 5V-tolerant DDC Data for Analog Interface; 4mA driving strength DDC_CLK Input w/ 5V-Tolerant DDC Clock for Analog Interface DDCROM_CLK Input w/ 5V-Tolerant DDC ROM Clock DDCROM_DAT I/O w/ 5V-tolerant DDC ROM Data;...
  • Page 70 3.5.3 function introduction to MP1430 1. Description The MP1430 is a step-down regulator with an internal Power MOSFET. It achieves 3A continuous output current over a wide input supply range with excellent load and line regulation. Current mode operation provides fast transient response and eases loop stabilization. Fault condition protection includes cycle-by-cycle current limiting and thermal shutdown.
  • Page 71 Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a resistive voltage divider from the output voltage. The feedback threshold is 1.222V. See Setting the Output Voltage section. Compensation Node. COMP is used to compensate the regulation control loop. Connect a series RC network COMP from COMP to GND to compensate the regulation control loop.

  • Page 72: Programmable Watchdog Timer

    # Dual 64KB In-System Programmable Flash EPROM banks (APFlash0 and APFlash1) # 4KB Auxiliary Flash EPROM for loader program (LDFlash) # 256 bytes scratch-pad RAM # 1 KB on-chip SRAM for MOVX instruction # Programmable Watchdog Timer # 6 channels of 8 bit PWM # Software Reset # Software programmable access cycle to external RAM/peripherals # Code protection...
  • Page 73 　 Screen proportion switch Video Output Switch1 Video Output Switch2 IIC clock IIC data SEL_I/P Progressive/Interlaced Scanning Switch AMP_MUTE Audio Amplifier Mute AMP_STB Audio Amplifier Standby PROGRAM STORE ENABLE: PSEN enables the external ROM data onto the Port 0 address/data PSEN bus during fetch and MOVC operations.
  • Page 74 composite and S-Video into component YCbCr. This chip includes four 10-bit 30-MSPS A/D converters. Prior to each A/D converter, each analog channel contains an analog circuit, which clamps the input to a reference voltage and applies a programmable gain and offset. A total of 10 video input terminals can be configured to any combination of RGB, YPbPr, CVBS, S-Video video inputs.
  • Page 75 VI_2_C inputs (or a combination thereof) can be supported. The inputs must be AC coupled. The recommended coupling capacitor is 0.1 μF. VI_3_A The possible input configurations are listed in the input select register 00h. VI_3_B VI_3_C VI_4_A Clock Signals XTAL1 External clock reference input.
  • Page 76 Host Interface I2C Data bus. I2C Clock input. Power Supplies NSUB Substrate ground. Connect to analog ground. CH1_A33GND CH2_A33GND 3 6 19 22 Analog 3.3V return. CH3_A33GND CH4_A33GND CH1_A33VDD CH2_A33VDD 4 5 20 21 Analog power. Connect to 3.3V. CH3_A33VDD CH4_A33VDD CH1_A18GND CH2_A18GND...
  • Page 77 AVID/GPIO Active Video indicator output Programmable general purpose I/O 3.5.6 function introduction to NCP1377 1. Description The NCP1377 combines a true current mode modulator and a demagnetization detector which ensures full borderline/critical Conduction Mode in any load/line conditions together with minimum drain voltage switching (Quasi- Resonant operation).
  • Page 78 3. Pin Definitions Symbol Function Description The auxiliary FLYBACK signal ensures discontinuous operation and Demag Core reset detection and OVP offers a fixed over voltage detection level of 7.2 V. By connecting an optocoupler to this pin, the peak current setpoint is Sets the peak current setpoint adjusted accordingly to the output power demand.
  • Page 79 # STAND-BY & MUTE FUNCTIONS # SHORT CIRCUIT PROTECTION # THERMAL OVERLOAD PROTECTION 3. Pin Definitions Pin Name Pin Type Function PW_GND OUT1+ Output LOUT+ OUTPUT OUT1- Output LOUT- OUTPUT 10V POWER Power AUDIO INPUT AUDIO_L _INPUT ＭＵＴＥ　Ｉ MUTE MUTE 　...
  • Page 80 3.5.8 function introduction to LA7952 1. Feature # On-chip driver with 4 inputs, 1 output, 75W termination. # On-chip 6dB amplifier. # Excellent crosstalk characteristic. # Wide band. # Input with DC restoration circuit. 2. Pin Definitions Pin Name Pin Type Function VIDEO OUT OUTPUT...
  • Page 81 # Integrated Burst Mode Oscillator and Modulator # Soft-On and Soft-Off Burst Envelope # Open Lamp Protection # Secondary Over-Current Protection # Dual-Mode Fault Timer # Available in TSSOP28 and SOIC28 Packages 3. Pin Definitions Name Description Secondary Current Feedback Input. Connect a current sense resistor from the cold end of the secondary winding to ground.
  • Page 82 Analog Brightness Control Input. The voltage range of 0V to 1.2V at ABRT sets the 3:1 dimming range for the lamp ABRT current. If analog dimming is not used, tie ABRT to VCC. Enable Input. Pull EN high to turn on the MP1048; low to turn it off. No Connect.
  • Page 83 Chapter Four Disassembly and Assembly Process In order to know structure of TV set LT2002S easily, directly and quickly, pictures are adopted here to present each link of assembly and disassembly process of the player to avoid operating blindly to damage elements.
  • Page 84 Panel flat cable 5. Take 2 TB4 10H white nickel screws and 6. Take down rear casing components, unplug TMT4 7H white nickel screw. button board flat cable and put rear casing components aside (do not scratch them). 7. Remove display screen: unplug flat cable 8.
  • Page 85 11. Remove 6TB 3 10H white nickel screws. 12. Remove 6 TB 3 10H white nickel screws. P/L connecting line 13. Remove 4 TB 3 10H white nickel screws. 14. Remove 4 TM3 6H white nickel screws and then take P/L connecting line slightly (please note back side of flat cable has double-sided adhesive tape).

  • Page 86: Section One Pcb Board

    Chapter Cinque PCB board & Circuit diagram Section One PCB board 5.1.1 Surface layer of Button Board SW401 SW404 SW403 SW406 SW405 SW402 SW407 SOURCE POWER VOL+ MEUN VOL- 42002S-0 CN401 VER:L061011 - 82 -...
  • Page 87 5.1.2 Bottom layer of Button Board D407 D405 D409 D406 D404 D402 D410 D408 D403 - 83 -...
  • Page 88 5.1.3 Surface layer of Main Board - 84 -...
  • Page 89 5.1.4 Bottom layer of Main Board - 85 -...
  • Page 90 5.1.5 Surface layer of power Board SIZE:118*78MM AC100-240V TC05 52008-3 VER:L061201 94V0 CU THK=1.6MM - 86 -...
  • Page 91 5.1.6 Bottom layer of power Board - 87 -...
  • Page 92 5.1.7 Surface layer of Boost Board R43 R44 D8 R45 D4 R40 D6 R28 R23C31 D3 C33 R24 R32R26 R21 C27 R19C18 D5R20 R17R18R7 5INV607-3 06.11.22 - 88 -...
  • Page 93 5.1.8 Bottom layer of Boost Board - 89 -...
  • Page 98 D408 IN4148 IN4148 D404 IN4148 D403 IN4148 D409 CN401 IN4148 D407 KEY4 KEY4 KEY3 KEY3 IN4148 D405 KEY2 KEY2 IN4148 D406 KEY1 KEY1 TO KEY BOARD IN4148 D402 IN4148 D410 SW401 SW402 SW403 SW404 SW405 SW406 SW407 POWER MEUN VOL+ VOL- SOURCE CN402B...
  • Page 99 225/X7R/25V 2N7002 10pF/3KV 25V/220uF 27:1860 LK200mH 25V/220uF 103/X7R/25V 2.2M 1N4148 MP1048 510ohm 225/X7R/25V AO4822 VCCL 10pF/3KV 105/X7R/10V 103/X7R/10V COMP OUTL 103/X7R/25V AO4822 223/X7R/25V 100K 225/X7R/25V 225/X7R/25V 473/X7R/10V 10pF/3KV 473/X7R 103/X7R/25V AO4822 150K VCCR 105/X7R/10V 0ohm DBRT OUTR ABRT 225/X7R/25V AO4822 10pF/3KV ENSYNC 223/X7R/25V...
  • Page 100 68K/3W 150UF/400V 24R/1206 0.47UF/275V 510K/1206 24R/1206 GBU805 Y336 471/50V 472/1kV 0.22UF/275V 104/0603 1000UF/25V +12V 90uH/5A MBR20100CT/TO-220 +12V/5A 334K/400V HER107 2mH/2A 22mH/2A L--GND 510K/1206 H-GND H-GND 1000UF/25V 1000UF/25V SCK10103MS1003 T4AL250V 1M/1206 1M/1206 270/1206 POWER SW HER105 4.75K(1%)/0603 18V/0.5W 6.8K/0603 2M/1206 1M/1206 4.7R/1206 1K/0603 HS817C/DIP4...

  • Page 101: Chapter Six Bom List

    Chapter six BOM List MATERIA MATERIAL NAME SPECIFICATIONS LOCATION L CODE LT2002S(RU) BLACK POWER BOARD 5449797 0090114 SMD RESISTOR 1/8W 0O± 5% 1206 JP2,JP3 0090521 SMD RESISTOR 1/8W 510K± 5% 1206 RA,RB 0090057 SMD RESISTOR 1/10W 4.7K± 5% 0805 0090072 SMD RESISTOR 1/10W 39K±...
  • Page 102 CONDUCT OIL 2100003 LEAD F 0.6 SHAPED 7.5mm 2100017 LEAD F 0.6 SHAPED 20mm 4210151 MACHINE-TAPPING SCREW B3×6H WHITE NICKEL VD4,Q1 LT2002S(RU) BLACK KEY-PRESS BOARD 5449336 0700001 SMD DIODE LS4148 D402~D408,D410,D409 1340145 LIGHT TOUCH RESTORE SWITCH VERTICAL TSAC-2 SW401~SW407 1940160 SOCKET 5P 2.0mm STRAIGHT FLEX...
  • Page 103 2110485 LEAD GROUNDING WIRE PIECE,HOLEF 4.3 1940142 SOCKET 2P 8.0mm STRAIGHT FLEX 2300006 FUSE 4AL 250V 1563786 PCB A2008-1 LT2002S(RU) BLACK RECEIVING BOARD OF REMOTE CONTROL 5449365 0620086 DUAL COLOR RADIATION DIODE 2.5RG59HW-A×5 RED GREEN D901 2360002 IR SENSOR HS0038B IR901 MAIN BOARD CN7 TO REMOTE 5P 250 2.0 1 5PSHIELD WITH WELD PIECE...
  • Page 104 019-01 3# CONDUCT GLUE O REMOTE 4631127 2002S(RU) CONTROL 5070558 PLASTIC BAG 210×70×0.05 PE PACK REMOTE CONTROLLER LT2002S(RU) BLACK TRANSFER BOARD 5449490 1940403 BTB SOCKET 21/20P 1.0mm HRS/D9-41S-1V 1940211 CABLE SOCKET 50P 0.5mm SMD,NEXT MEET WITH CLASP CN2 1633663 PCB...
  • Page 105 MATERIA MATERIAL NAME SPECIFICATIONS LOCATION L CODE 0090001 SMD RESISTOR 1/16W 0O± 5% 0603 L9,L48~L54 0100019 SMD RESISTOR NETWORKS 1/16W 33O± 5% 8P RP1~RP8 C2~C7,C14~C38,C40,C44,C45,C136, 0310042 SMD CAPACITOR 50V 15P± 5% NPO 0603 C137,C159 0310047 SMD CAPACITOR 50V 101± 5% NPO 0603 0310066 SMD CAPACITOR 50V 102±...
  • Page 106 MATERIA MATERIAL NAME SPECIFICATIONS LOCATION L CODE SMD VOLTAGE REGULATOR 0700137 11V± 5% 1/2W MINIMELF DIODE 0780198 SMD TRIODE 2S1015 Q5,Q13 0880504 IC 24C32N SOP 02607649 CD C11T 50V1U± 20%5×11 2 BELT CE31 CE5,CE9,CE20,CE21,CE38,CE41,CE 02607359 CD C11T 16V47U± 20%5×11 C5 BELT 02606869 CD C11T 25V220U±...
  • Page 107 1940005 SOCKET 6P 2.0mm 1940006 SOCKET 6P 2.5mm 1940003 SOCKET 4P 2.5mm 1940024 SOCKET 5P 2.0mm CN2,CN7 3580236 HEAT RADIATION PIECE 18×11×6.9 1509 FOR U11 LT2002S(RU)BLACK PRODUCT CODE 5840114 PROGRAM FLASH ROMLT2002S-0A(128K) 0911865 0882637 IC 79E63240PN PLCC - 103 -...

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