Toshiba CN27E90 Technical Training Manual
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Toshiba CN27E90 Technical Training Manual

Toshiba CN27E90 Technical Training Manual

N5ss (tg-1, c) chassis
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NTDCTV05
TECHNICAL TRAINING MANUAL
N5SS (TG-1, C) CHASSIS
COLOR TELEVISION
PRINTED IN JAPAN Aug. 1995 So

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Summary of Contents for Toshiba CN27E90

  • Page 1 NTDCTV05 TECHNICAL TRAINING MANUAL N5SS (TG-1, C) CHASSIS COLOR TELEVISION PRINTED IN JAPAN Aug. 1995 So...

  • Page 2: Table Of Contents

    Contents SECTION I OUTLINE ..............6 1. OUTLINE OF N5SS CHASSIS (CN32E90, CN35E90) ..............7 2. PC BOARD CONFIGURATION ......................7 3. MAJOR SPECIFICATIONS (NEW FUNCTIONS IN ADDITION TO THOSE OF N5SS) ..7 4. MODIFICATIONS ON CHASSIS ..................... 7 5.
  • Page 3 SECTION V A/V SWITCHING CIRCUIT ........44 1. OUTLINE ............................45 2. IN / OUT TERMINALS ........................45 3. CIRCUIT OPERATION ........................45 SECTION VI VIDEO PROCESSING CIRCUIT ......47 1. OUTLINE ............................48 2. SIGNAL FLOW ..........................48 3. CIRCUIT OPERATION ........................48 SECTION VII V/C/D/IC ..............
  • Page 4 SECTION XI HORIZONTAL DEFLECTION CIRCUIT....69 1. OUTLINE ............................70 2. HORIZONTAL DRIVE CIRCUIT ....................70 3. BASIC OPERATION OF HORIZONTAL DRIVE ................ 71 4. HORIZONTAL OUTPUT CIRCUIT ....................74 5. HIGH VOLTAGE GENERATION CIRCUIT ................. 79 6. X-RAY PROTECTION CIRCUIT ....................82 7.
  • Page 5 SECTION XV DSP CIRCUIT ............109 1. ORIGINS OF DOLBY SURROUND ..................... 110 2. THE DOLBY MP MATRIX ......................110 3. THE DOLBY SURROUND DECODER ..................111 4. DSP CIRCUIT ........................... 111 5. DSP (Digital Surround Processor) IC ..................... 114 6.

  • Page 6: Section I

    SECTION I OUTLINE...

  • Page 7: Outline Of N5Ss Chassis (Cn32E90, Cn35E90)

    3. MAJOR SPECIFICATIONS (NEW 1. OUTLINE OF N5SS CHASSIS FUNCTIONS IN ADDITION TO THOSE (CN32E90, CN35E90) OF N5SS) The N5SS chassis is a complete bus control type chassis where the deflection circuit is controlled by a newly (1) EOS (Extended-Data-Service) developed I2C-bus line control system.

  • Page 8: Construction Of Chassis

    5. CONSTRUCTION OF CHASSIS...

  • Page 9: Location Of Controls

    6. LOCATION OF CONTROLS 6-1. TV Set For specific use of each control, consult the corresponding page numbers in brackets. POWER Fig. 1-2...
  • Page 10 Fig. 1-3...
  • Page 11 6-2 Location of Controls (Remote Control) Only the buttons that are used to operate the TV set are described here. For details on the use of each control, refer to pages in brackets. Fig. 1-4...
  • Page 12 6-3 Monitor Panel This TV set is equipped with S-VIDEO INPUT jacks, VIDEO/AUDIO INPUT jacks, VIDEO/AUDIO OUTPUT jacks, VARIABLE AUDIO OUTPUT jacks, PIP AUDIO OUTPUT jacks and EXTERNAL SPEAKER terminals for connecting your desired video/audio equipment. Fig. 1-5 VIDEO 1/VIDEO 2/VIDEO 3 IN Jacks — PIP AUDIO OUT Jacks —...

  • Page 13: Cn32D90 Block Diagram

    7. CN32D90 BLOCK DIAGRAM...

  • Page 14: Us, Canada] Specification For Model's 1995

    8. [US, CANADA] SPECIFICATION FOR MODEL's 1995 CHASSIS MODEL Nbr CN27E90 CX32E70 CN32E90 CE35E15 CF35E50 DERIV SPECIFICATION HITACHI *TDD *TDD 1 Picture Tube *FST-D/T NF-D/T NF-D/T *FST-D/T FST-D/T 2 Channel Capacity 181ch 181ch 181ch 181ch 181ch 3 C. Caption 4 MTS with dbx...
  • Page 15 CHASSIS MODEL Nbr CX35E60 CX35E70 CX35E81 CN35E90 CN35E95 CONSOLE CINEMA SPECIFICATION 1 Picture Tube FST-D/T NF-D/T NF-D/T NF-D/T NF-D/T 2 Channel Capacity 181ch 181ch 181ch 181ch 181ch 3 C. Caption 4 MTS with dbx 5 Bass, Tre, Balance 6 Sub-Audio-Program 7 Remote band unit *A-Univ (42k) *A-Univ (42k)

  • Page 16: Tuner, If/Mts/S.pro Module

    SECTION II TUNER, IF/MTS/S.PRO MODULE...

  • Page 17: Circuit Block

    1. CIRCUIT BLOCK IF/MTS/S.PRO Module MVUS34S EL466L output Sound VIF/SIF S.PRO Circuit Multiplex Tuner Circuit Filter Circuit RF AGC C-IN R-IN L-IN TP12 Video output R-OUT L-OUT C-OUT R-OUT L-OUT To A/V switch circuit AFT output (L+R) -OUT Fig. 2-1 Block diagram 1-1.

  • Page 18: Tuner

    2-2-2. Terminals (Tuner section) 2. TUNER Name Function 2-1. Outline IF OUT IF outputs (P=45.75 MHz, C=42.17 MHz, (1) Type name: EL466L S=41.25 MHz) (2) Applicable 181CH Tuner power supply (9V) (3) I2C-bus version RF AGC Gain control terminal to obtain constant (4) PLL-integrated IF output Control voltage to select channels...

  • Page 19: If/Mts/S.pro Module

    3. IF/MTS/S.PRO MODULE 3-1-2 Video PIF Circuit A PIF detector switching carrier is oscillating at a frequency The IF/MTS/S.PRO module (MVUS34S) limits bandwidth adjusted to 45.75 MHz with L051 (VCO CW coil) under no of IF signals and detects video and audio signals. The module RF signal input.
  • Page 20 4 . 5 M H z S I F S I G N A L Z 0 0 3 F M D E T . C O I L L 0 5 3 S I F B A N D W I D T H S I F L I M I T F M D E T .
  • Page 21 3-1-4. Audio Multiplex Demodulation Circuit Then, both are fed to the matrix circuit. At the same time, The sound multiplex composite signal FM-detected in the each of the stereo pilot signal fH and the SAP pilot signal 5fH PIF circuit enters pin 12 of HIC (hybrid IC) in passing is also demodulated to obtain an identification voltage.
  • Page 22 3-1-5. A.PRO Section (Audio Processor) All these processing are carried out according to the BUS The S.PRO section has following functions. signals sent from a microcomputer. (1) Woofer processing (L+R output) (2) High band, low band, balance control Fig. 2-6 shows a block diagram of the A.PRO IC. (3) Sound volume control, cyclone level control (4) Cyclone ON/OFF TA1217N...

  • Page 23: Pip Tuner

    4. PIP TUNER Lable Name Lot No. TUNER VIF/SIF SECTION FILTER CIRCUIT RF AGC VIDEO AUDIO OUTPUT OUTPUT OUTPUT Fig. 2-7 Terminal No. Name 4-1. Outline S-CLOCK The PIP tuner (EL922L) consists of a tuner and an IF block S-DATA integrated into one unit.

  • Page 24: Channel Selection Circuit

    SECTION III CHANNEL SELECTION CIRCUIT...

  • Page 25: Outline Of Channel Selection Circuit System

    I C bus type frequency synthesizer equipped in the tuner, and by setting a band switch Toshiba made 8 bit microcomputer TLCS-870 series for TV data which selects the UHF or VHF band. receiver, TMP87CS38N-3152 is employed for QA01.

  • Page 26: Microcomputer

    3. MICROCOMPUTER Microcomputer TMP87CS38N-3152 has 60k byte of ROM IIC device controls through I2C bus. (Timing chart : See fig. capacity and equipped with OSD function inside. 3-1) The specification is as follow. • LED uses big current port for output only. •...

  • Page 27: Microcomputer Terminal Function

    4. MICROCOMPUTER TERMINAL FUNCTION TMP87CS38N3152 (QA01) P40 (PWM0) REM OUT P41 (PWM1) MUTE P42 (PWM2) SP MUTE SDA1 P43 (PWM3) SDA0 IIC- SCL1 P44 (PWM4) SCL0 POWER SYNC AV1 P45 (PWM5) (TC3)P31 RMT IN P46 (PWM6) (RXIN)P30 SW IN P47 (PWM7) RESET RESET P50 (PWM8/TC2)
  • Page 28 << MICROCOMPUTER TERMINAL NAME AND OPERATION LOGIC >> Terminal Name Function In/Out Logic Remarks INPUT BALANCE PWM out REM OUT REMOTE CONTROL Remote control output SIGNAL OUT MUTE SOUND MUTE OUT Sound mute output SP MUTE SPEAKER MUTE In muting = H DEF POW POWER POWER ON/OFF OUT...

  • Page 29: Eeprom (Qa02)

    5. EEPROM (QA02) EEPROM (Non volatile memory) has function which, in spite of power-off, memorizes the such condition as channel selecting data, last memory status, user control and digital processor data. The capacity of EEPROM is 8k bits. Type name is 24LC04BI/ P or ST24C04CB6, and those are the same in pin allocation and function, and are exchangeable each other.

  • Page 30: System Block Diagram

    7. SYSTEM BLOCK DIAGRAM QA01 TMP87CS38N-3152 QA02 SDA 1 SCL 1 H001 MEMORY 24LC04B1/P MAIN U/V TUNER REMOTE EL446L SENSOR UNIT SCL 0 HY01 SDA 0 SUB U/V TUNER EL922L KEY-A KEY SWITCH H. SYNC PULSE HSYNC KEY-B VSYNC PULSE VSYNC POWER Q501...

  • Page 31: Local Key Detection Method

    8. LOCAL KEY DETECTION METHOD Local key detection in the N5SS chassis is carried out by using analog like method which detects a voltage appears at local key input terminals (pins 17, 18) of the microcomputer when a key is pushed.

  • Page 32: Remote Control Code Assignment

    9. REMOTE CONTROL CODE ASSIGNMENT Custom codes are 40-BFH Custom codes are 40-BFH Applicable Applicable Code Applicable Conti- Code Applicable Conti- Function to remote Function to remote to TV set nuty to TV set nuty control control 0 Channel PIP STILL 1 Channel PIP ON/OFF 2 Channel...
  • Page 33 Custom codes are 40-BFH Custom codes are 40-BFH Applicable Code Applicable Conti- Code Applicable Conti- Function to remote Function to TV set nuty to TV set nuty control A0H SUB-BRIGHT ADJUSTMENT A1H G. DRIVE ADJUSTMENT A2H B. DRIVE ADJUSTMENT C4H PIP LOCATE CUTOFF DRIVE 40H INITIALIZING, HORIZONTAL ONE LINE A5H R.
  • Page 34 Custom codes are 40-BFH Code Applicable Conti- Function to TV set nuty E0H PINCUTION/EW CORER (PARA/CNR) VERTICAL S-CUVE CORRECTION/VERTICAL M-CURVE CORRECTION (VSC/FVC) EAH HORIZONTAL WIDTH (WID/PARA) EBH TRAPEZOIDE CORRECTION (TRAP) ECH TEST TONE EDH DOLBY EEH 3 DIMENTIONAL Y/C SEPARATION EFH DPC E0H STANDARD (HEIGHT LINEARITY) (VLIN/HIT) E1H WIDE (HEIGHT LINEARITY) (VLIN)

  • Page 35: Entering To Service Mode

    10. ENTERING TO SERVICE MODE 12. SERVICE ADJUSTMENT 1. PROCEDURE 1. ADJUSTMENT MENU INDICATION ON/OFF : (1) Press once MUTE key of remote hand unit to MENU key ( on TV set) indicate MUTE on screen. 2. During display of adjustment menu, the followings are (2) Press again MUTE key of remote hand unit to keep effective.

  • Page 36: Failure Diagnosis Procedure

    13. FAILURE DIAGNOSIS PROCEDURE Model of N5SS chassis is equipped with self diagnosis function inside for trouble shooting. 1. CONTENTS TO BE CONFIRMED BY CUSTOMER Contents of self diagnosis Display items and actual operation A. DISPLAY OF FAILURE INFORMATION Power indicator lamp blinks and picture does not come. IN NO PICTURE (Condition of display) 1.
  • Page 37 4. UNDERSTANDING SELF DIAGNOSIS INDICATION In case that phenomenon always arises. See figure 3-4 . Item Contents Instruction of results BUS LINE Detection of bus line short Indication of OK for normal result, NG for abnormal Indication of OK for normal result Indication of failure place in abnormality (Failure place to be indicated) QA02 NG, H001 NG, Q501 NG, H002 NG...

  • Page 38: Trouble Shooting Chart

    14. TROUBLE SHOOTING CHART (1) TV DOES NOT TURNED ON TV does not turned on. Relay sound Check of voltage at pin 7 of QA01 (DC 5V). Check power circuit. 8MHz oscillation waveform at pin 32 of QA01. Check OSC circuit. Replace QA01.
  • Page 39 (2) NO ACCEPTION OF KEY-IN Key on TV Voltage change at pins 17, 18 of QA01 (5V to 0V). Check key-in circuit. Replace QA01. Remote unit key Pulse input at pin 35 of QA01, When remote unit key is pressed. Check tuner power circuit.
  • Page 40 (4) MEMORY CIRCUIT CHECK Memory circuit check Voltage check at pin 8 of QA02 (5V). Check power circuit. Pulse input at pins 5 and 6 of QA02 in memorizing operation. Check QA01. Replace QA02. Note: Use replacement parts for QA02. Adjust items of TV set adjustment.

  • Page 41: Audio Output Circuit

    SECTION IV AUDIO OUTPUT CIRCUIT...

  • Page 42: Outline

    1. OUTLINE Configuration of the audio circuit and signal flow are given in Fig 4-1. A/V PCB VIF+MTS+S.PRO FOR PIP MODULE ICV01 IF MODULE CHILD MOTHER AUDIO PIP OUT (AUDIO) VIDEO 1 VIDEO 1 VIDEO 2 VIDEO VIDEO 2 OUTPUT Q670 VIF+MTS+A.PRO TERMINAL...

  • Page 43: Audio Out Ic

    2. AUDIO OUT IC 2-1. OUTLINE In the model, CN32E90, the main amplifiers and woofer output amplifiers use bipolar IC TA8256H and develop out powers of 10W x 2+13W. 2-2. THORY OF OPERATION 2-2-1. Operatin of TA8256H The TA8256H is a modified version of TA8128AH used in the N4SS chassis as an audio ouput IC.

  • Page 44: A/V Switching Circuit

    SECTION V A/V SWITCHING CIRCUIT...

  • Page 45: Outline

    With S-terminal ..Excepting CF35E50, CL37E56, CE35E15 VIDEO3 (Back) ........Only for CF35E50, CL37E56, CE35E15 OUTPUT VIDEO OUTPUT (V, L, R) ....Excepting CN27E90 AUDIO ON SUB-PICTURE ....Only for CN32E90, CN35E90, CN35E95 3. CIRCUIT OPERATION This circuit consists of A/V SW IC; TA1218N (QV01), and selects signals from U/V tuner (Main), U/V tuner (Sub), E1, E2 and E3.
  • Page 46 AV SW CIRCUIT TUNR/IMA V Aout L/R V out QV01 TA1218N L/R in C in QA01 R in SYNC OUT SYNC in VIDEO 3 S in L in PIP TV in COMB C in PIP L in FILTER Y in R in Y out VIDEO 1...

  • Page 47: Video Processing Circuit

    SECTION VI VIDEO PROCESSING CIRCUIT...

  • Page 48: Outline

    1. OUTLINE signals, and is converted to original color signal (R,G,B) by RGB matrix. Next the signal is superimposed with OSD signal to be output to pins 41, 42 and 43, and is This circuit converts and amplifies video signal (Luminance supplied to CRT Drive circuit.
  • Page 49 Terminals concerning Video / Chroma circuit of Q501 are explained here. CW OUTPUT 3.58MHz which is synchronized to burst signal is output, and is used for clock of comb filter. SCP OUTPUT The signal which is superimposed with burst gate pulse and blanking pulse is output. It is not used in this time.
  • Page 50 CW OUTPUT DAC 2 (2bit) COLOR IDENT. OUTPUT DAC 1 (1bit) SCP OUTPUT MONITOR OUTPUT SECAM CONTROL COLOR LIMITER Y1 OUTPUT Y2 INPUT Q OUTPUT Q INPUT I OUTPUT I INPUT 1H DL CONTROL BLACK PEAK HOLD XTAL 3 APL DET. XTAL 2 VSM OUTPUT Ym INPUT...
  • Page 51 Fig. 6-2 Block diagram of Video Processing circuit...

  • Page 52: V/C/D/Ic

    SECTION VII V/C/D/IC...

  • Page 53: Outline

    1. OUTLINE This IC enables more precise picture setting than that of former IC (TA8845N) by means of large scale employment of IIC bus, and reduces many peripheral components by containing filters inside. The main features (comparing TA8845) are as follows. 2.
  • Page 54 VCD BLOCK DIAGRAM (TA1222N) GND (DEF) VCC (DEF) H. V. PHASE DET PHASE DET H. PHASE H. DUTY H. DRIVE 32 FM VCO H. BLK SYNC SEP <APC-1> <APC-2> SHIFT V. Sep 16 V. SEP Y.P OUT 31 VER OUT COUNT DOWN PARABOLA COUNT DOWN...

  • Page 55: Pip Module

    SECTION VIII PIP MODULE...
  • Page 56 PMUS 02H (SN:23148232) B-Y OFFSET R-Y OFFSET TINT RY54 RY55 RY50 NAME NAME R OUT G OUT B OUT PIP VIDEO...
  • Page 57 PMUS02H <BLOCK DIAGRAM OF PIP MODULE> RY55 RY54 PIP VIDEO R OUT VIDEO R OUT G OUT G OUT B OUT Y-OUT SLICE B OUT WAVE FORM HDCN HDPN MODULATION VDCN VDPN QY01 QY03 QY01 m PC1832GT TC9083F m PC 1832GT (PIP V/C/D) (PIP PROCESSOR) (PIP V/C/D)

  • Page 58: Sync Separation, H-Afc, H-Oscillator Circuits

    SECTION IX SYNC SEPARATION, H-AFC, H-OSCILLATOR CIRCUITS...

  • Page 59: Sync Separation Circuit

    1. SYNC SEPARATION CIRCUIT The sync separation circuit separates a sync signal from a video signal and feeds it to an H and V deflection circuits. The separation circuit consists of an amplitude separation (H and V sync separation circuit) and a frequency separation circuit (V sync separation circuit) which performs the separation by using a frequency difference between H and V.

  • Page 60: H Afc (Automatic Frequency Control) Circuit

    1-1-2. V Sync Separation Circuit First, phases of a 32 fH counted-down signal and a H sync To separate a V sync signal from the composite sync signal signal contained in broadcasting signal are compared in the consisting of V and H sync signals mixed, two stages of AFCI loop and the loop develops an H pulse signal for the integration circuits are provided inside the IC.

  • Page 61: H Oscillator Circuit

    distortion due to phase difference are incompatible. That is,to improve the jitter under poor field strength, response speed must be slowed by lowering the AFC sensitivity. On the other hand, to improve distortion due to the phase difference, the response must be increased by increasing the AFC sensitivity.
  • Page 62 (2) The AFC voltage controls frequency (32 x fH) of the oscillator (VCO). Fig. 9-5 shows the control characteristics of the VCO. (3) The H output is obtained by dividing the 32 x fH (503 High kHz) of the oscillator with flip-flops. Fig. 9-6 shows the block diagram of this count down circuit.

  • Page 63: Vertical Output Circuit

    SECTION X VERTICAL OUTPUT CIRCUIT...

  • Page 64: Outline

    1. OUTLINE As can be seen from the block diagram, the sync circuit and the V trigger circuit are contained in Q501 (TA1222N), and the sawtooth generation circuit and amplifier (V drive circuit) contained in Q302 (TA8859AP). The output circuit and pump-up circuit circuits are included in Q301 (TA8427K).

  • Page 65: Output Circuit

    2. V OUTPUT CIRCUIT 2-1. Actual Circuit D309 C322 R309 C308 +27V D301 C313 R329 R303 Q301 L301 R336 Q302 Q501 C321 C307 R307 L462 R320 R301 R306 Q312 Q311 C314 C306 R313 R330 R344 C305 +27V R304 R305 C319 Fig.
  • Page 66 2-3. V Output yoke. Q3 turns on for first half of the scanning period 2-3-1. Circuit Operation and allows a positive current to flow into the deflection The V output circuit consists of a V driver circuit Q302, yoke (Q3 C306 R305 GND), and Q4...
  • Page 67 (4) To decrease the collector loss of Q3, the power supply (6) Since pin 7 of a transistor switch inside Q301 is connected voltage is decreased during scanning period as shown to the ground for the scanning period, the power supply in Fig.
  • Page 68 2-4. V Linearity Characteristic Correction 2-4-1. S-character Correction (Up-and Down-ward Extension Correction) A parabola component developed across C306 is integrated by R306 and C305, and the voltage is applied to pin 6 of Q302 to perform S-character correction. 2-4-2. Up-and Down-ward Linearity Balance A voltage developed at pin 2 of Q301 is divided with resistors R307 and R303, and the voltage is applied to pin 6 of Q301 to improve the linearity balance characteristic.

  • Page 69: Horizontal Deflection Circuit

    SECTION XI HORIZONTAL DEFLECTION CIRCUIT...

  • Page 70: Outline

    1. OUTLINE The H deflection circuit works to deflect a beam from left to right by flowing a sawtooth waveform of 15.734 kHz into the DY H deflection coil. 2. HORIZONTAL DRIVE CIRCUIT The H drive circuit works to start the H output circuit by applying HVCC (Q501 DEF power source) to pin 22 of Q501 (TA1222N) and a bias to the H drive transistor Q402 at the main power on.

  • Page 71: Basic Operation Of Horizontal Drive

    3. BASIC OPERATION OF HORIZONTAL DRIVE turn off the transistor, a sufficiently high, reverse voltage A sufficient current must flow into base of the horizontal must be applied to the base. output transistor to rapidly make it into a saturated (ON) (3) When the transistor is on (collector current is maximum) condition or a cut off (OFF) condition.
  • Page 72 3-2. Drive System 3-2-2. OFF drive system 3-2-1. ON drive system When the drive transistor is on, the horizontal output transistor When the drive transistor is on, the horizontal output transistor is off. also turns on. Merit: Merit: • Energy balance between on and off periods of the drive •...

  • Page 73: Circuit Description

    3-3. Circuit Description In the N5SS chassis, the off drive system is employed. (1) When Q1 inside Q501 is turned on, Q402 base is forward biased through 9 V pin 22 of Q501 (H. VCC) pin 23 of Q501 (H. Out) R411/R410 resistor divider, and then, Q402 collector current flows through 125V...

  • Page 74: Horizontal Output Circuit

    4. HORIZONTAL OUTPUT CIRCUIT The horizontal output circuit applies a 15.734 kHz sawtooth wave current to the deflection coil with mutual action of the horizontal output transistor and the damper diode, and deflects the electron beam from left to right in horizontal direction. T461 S-charactor capacitor...
  • Page 75 4-1. Theory of Operation Description of the basic circuit 4-1-1. Operation of Basic Circuit 1. t1~t2: (1) To perform the horizontal scanning, a 15.734 kHz A positive pulse is applied to base of the output transistor sawtooth wave current must be flown into the horizontal from the drive circuit, and a forward base current is flowing.
  • Page 76 6. t4~t6: t2 t3 t4 t5 For this period. C0 is charged with the deflection current having opposite polarity to that of the deflection current base voltage stated in "3.", and when the resonant capacitor voltage exceeds VCC, the damper diode D conducts. The deflection current decreases along to an exponential function (approximately linear) curve and reaches zero at t6.
  • Page 77 4-1-2. Linearity Correction (LIN) (1) S-curve Correction (S Capacitor) Pictures are expanded at left and right ends of the screen even if a sawtooth current with good linearity flows in the deflection t2 = t1 t2 > t1 coil when deflection angle of a picture tube increases. This <...
  • Page 78 total are obtained. (2) Left-right Asymmetrical Correction (LIN coil) 4-1-3. Horizontal Linearity, M-character Correction In the circuit shown in Fig. 11-11 a, the deflection coil Circuit current iH does not flow straight as shown by a dotted line in Since deflection angle increases with size of picture tube the figure b if the linearity coil does not exist, by flows as increases, a M character trend which compresses a picture shown by the solid line because of effect of the diode for a...

  • Page 79: High Voltage Generation Circuit

    which has two times the H oscillator frequency. 5. HIGH VOLTAGE GENERATION CIRCUIT The high voltage generation circuit develops an anode voltage for the picture tube, focus, screen, CRT heater, video output (210V) and so on by stepping up the pulse voltage developed for flyback period of the horizontal output circuit with the FBT, and supplies the power to various circuit.
  • Page 80 5-1. Theory of Operation 5-1-1. +210V For the flyback period, pulses are stacked up to DC +125V with FBT, and the voltage is rectified by D406 and filtered +115V by C446. 5-1-2. +27V Pin 4 of the FBT is grounded and the shaded area of negative pulse developed for opposite period of the flyback period is Fig.
  • Page 81 5-2. Operation Theory of the Harmonic Non-Resonant System and Tuned Waveforms The high voltage coil is of film multi-layer winding type and the coils are isolated into seven blocks. Each block is connected through a diode. The basic operation is described in the case of 4 blocks construction for simplification.

  • Page 82: X-Ray Protection Circuit

    frequency, and the turned waveform is shown in Fig. 11-17. 6. X-RAY PROTECTION CIRCUIT 1. Outline In case picture tube using high voltage, when high voltage rises abnormally due to components failure and circuit malfunction, there is possible danger that X-RAY leakage increases to affect human body.

  • Page 83: Over Current Protection Circuit

    first. 7. OVER CURRENT PROTECTION CIRCUIT 1. Outline If main power (125V) current increases abnormally due to components failure, there is possible danger of the secondary damage like failure getting involved in other part failure, and abnormal heating. To prevent this, over current protection circuit is equipped, which detects current of main B line to turn off power relay in abnormal situation.

  • Page 84: Kink Correction Circuit

    To restart TV set, repair failure first. the reverse operation will occur. 8. KINK CORRECTION CIRCUIT 2. Circuit Description To correct the kink damping circuit is added between the main B power line and the S character capacitor as shown in 1.

  • Page 85: Deflection Distortion Correction Circuit (Side Dpc Circuit)

    SECTION XII DEFLECTION DISTORTION CORRECTION CIRCUIT (Side DPC Circuit)

  • Page 86: Deflection Distortion Correction Ic (Ta8859P)

    1. DEFLECTION DISTORTION CORRECTION IC (TA8859P) (3) V S-character correction 1-1. Outline (4) V picture position (neutral voltage setting) The deflection distortion correction IC (TA8859AP), in (5) V M-character correction combination with a V/C/D IC (TA8859AP) which has a V (6) V EHT correction pulse output, performs correction for various deflection (7) H amplitude...

  • Page 87: Side Dpc

    2. SIDE DPC and the output circuit. 2-1. Outline The circuit can be controlled through the I2C bus. That is, the Since the deflection coil used in 29 and 34" type of N5SS parabola waveform and DC voltage obtained by controlling chassis is not a DPC free type left and right pin-cushion E/W output (pin 2) of Q302 (TA8859P) through the bus is distortion must be corrected with a circuit.

  • Page 88: Diode Modulator Circuit

    3. DIODE MODULATOR CIRCUIT high voltage of FBT also develops a constant voltage. Fig. 12-4 shows a basic circuit of the diode modulator used When the negative pulse developed at the point B is integrated in the N5SS. with Lm and Csm, its average value appears at Csm as a A key point in the N5SS chassis shown in Fig.

  • Page 89: Actual Circuit

    4. ACTUAL CIRCUIT In the actual circuit, the resonant capacitor is split into two as shown in Fig. 12-7. One, C440, is inserted between the collector of the H. OUT transistor and ground and another C444 inserted between the collector and emitter. In Fig. 16- 7, C440 is expressed as C1 and C444 as C2, and the resonant current path for the flyback period is shown by arrows.
  • Page 90 4-1. Basic Operation and Current Path 4-1-2. First Half Scanning Period 4-1-1. Later Half Scanning Period When the base drive current decreases and the H. OUT When the power is turned on, the power supply voltage VB transistor is turned off, each energy stored in LDY, Lm, Lp is applied to Cs and Csm, and the Cs acts as a power source of FTB is transferred to C1, C2 and C3, respectively, and the for a later half of the scanning period for which the H.
  • Page 91 4-1-3. Later Half of Flyback Period 4-1-4. First Half of Scanning Period All energy in the coil has been transferred to the resonant When the flyback period completes, the damper diode DD capacitors at the center of the flyback period, and the voltage and the modulation diode DM turn on, and the Iy and Im shows the maximum value.

  • Page 92: Closed Caption/Eds Circuit

    SECTION XIII CLOSED CAPTION/EDS CIRCUIT...

  • Page 93: Outline

    1. OUTLINE CC / EDS circuit extracts data of CC (Closed Caption) and EDS (Extended Data Services) from input video signal, and decode them to generate display signal. Major feature of CC/EDS circuit of TG1-C chassis is as follow. (1) Employing 1 chip decoder of stand alone type (2) Acceptable of field 2 data ( CAPTION 3, 4 TEXT 1, 2 EDS) as well as field 1 data ( CAPTION 1, 2 TEXT 1, 2)

  • Page 94: Display Format

    3. DISPLAY FORMAT Character display area of caption mode and text mode consists of 32 characters x 15 rows as shown in fig. 13-2. On front and back of each row, 1 character blank area is respectively added. In caption mode, up to 8 rows among 15 rows can be displayed at the same time.

  • Page 95: Circuit Operation

    4. CIRCUIT OPERATION Block diagram of CC / EDS circuit is shown in figure 13-4, and block diagram of QM01 is shown in figure 13-5. Video signal which is input to pin 9 of UM01 is changed to 1 Vp-p signal which is band-limited to 600kHz by the input circuit, and it is supplied to pin 7 of QM01.
  • Page 96 Fig. 13-4 CC /EDS circuit block diagram...
  • Page 97 Sllced Data Data MOD Data Sllcer Data Recovery & XFR BUF DLCK COMP Video Clamp Data CLK Recovery Display Sllce Level SYNC Sllcer CSYNC Command Processor Timing Logic COMP SYNC CHAR Decoder Control Vertical CTR And Control Horizontal Counter Output Logic DOT CLK Phase/...

  • Page 98: Power Circuit

    SECTION XIV POWER CIRCUIT...

  • Page 99: Outline

    1. OUTLINE Block diagram of power circuit is shown in fig. 14-1. Power circuit consists of stand-by power supply (power transformer) which supplies power to microcomputer, and main power supply which supplies power to H. OUT, AUDIO OUT and signal process circuits. Power for V. OUT, VIDEO OUT and the like is supplied from flyback transformer of H.

  • Page 100: Rectifying Circuit And Standby Power Supply

    2. RECTIFYING CIRCUIT AND STANDBY POWER SUPPLY diode and performs rectification and smoothing together Rectifying circuit is a circuit to generate dc from ac 120V. with C810. R801 is a resistor to regulate inrush current D899 is a varistor to absorb surge (ex. lightning) arose and to suppress rush current in switch-on.

  • Page 101: Outline Of Current Resonant Type Supply

    4. OUTLINE OF CURRENT RESONANT TYPE SUPPLY Basic configuration of current resonant type power supply used in CN32E90 is shown on figure 14-3. Basic operation is as follow. Primary winding of converter trans and resonant capacitor are connected in series to consist of LC series resonant circuit.

  • Page 102: Actual Circuit

    6. ACTUAL CIRCUIT Two MOS FET’s, driver which drives FET’s and frequency control IC are combined inside HIC (Q801 ). Converter transformer T862 is designed to have loose coupling between the primary and the secondary, and to have some extent of leakage inductance. This is the reason why L and C (leakage inductance and resonant capacitor) are resonated during period that rectifying circuit (diode) connected to the secondary winding conducts.
  • Page 103 << BLOCK DIAGRAM AND PIN FUNCTION >> HO G(H) START Logic DELAY LATCH CONTROL CONT G(L) Fig. 14-6. STR-Z3201 block diagram Pin No. Symbol Function Half bridge power input G(H) High side MOS FET gate High side gate drive output Control section ground Capacitor connection terminal for oscillation CONT...
  • Page 104 DATE TIME CT PIN VOLTAGE =2.5V OSC OUT SIGNAL (PIN11) LOW SIDE GATE VOLTAGE (PIN2) HIGH SIDE GATE VOLTAGE (PIN 15) PUSH-PULL PIN VOLTAGE OUT VOLTAGE (PIN 1) (PIN 15) PUSH-PULL OUT CURRENT Fig. 14-7 Waveform at each pin...

  • Page 105: Other Power Circuit

    7. OTHER POWER CIRCUIT Power supply circuits excepting main and standby supply circuits are explained here. Power supplied from T461 (Flyback transformer) of H. deflection circuit is shown in figure 13-8. Flyback transformer supplies 200V for video output from pin 3, 27V for V. out circuit from pin 6, and -27V for side DPC circuit from 5 pin respectively.

  • Page 106: Protector Module (Z801)

    8. PROTECTOR MODULE (Z801) line, Tr8 turns on to supply base current into Tr6 through CN32E90 employs protector module which combines in one ZD4. In case of X-RAY protection circuit, when high voltage package protection circuits for X-RAY protection and over increases abnormally, Tr10 and Tr9 turns on to supply base current protection, and error amplifier for +B voltage current into Tr6 through D3, then this causes Tr6 and Tr5...
  • Page 107 TROUBLESHOOTING CHART OF POWER CIRCUIT No raster Check/Repair AC circuit Fuse F801 breaks Replace F801 Is the following point short? Replace Fuse F860 breaks #1-#14, #1-#15, Q801, F860 #14-#15 of Q801 Replace F860 Instantly turns ON and Check/Repair then turns OFF immediately D801, R810 Voltage across C810 Check relay SR81...
  • Page 108 (No RASTER) No RASTER Red lights Check/Replace Is the status of power Check F470 F470, Q404 LED? Red blinks Is voltage at pin 22 (H-Vcc) of Q501 9V? Check peripherals of start circuit Q430 Short R370 and turn Red blinks Check peripherals of V.out and audio Vcc power on again...

  • Page 109: Dsp Circuit

    SECTION XV DSP CIRCUIT...

  • Page 110: Origins Of Dolby Surround

    1. ORIGINS OF DOLBY SURROUND into left, center equally into left and right, and right into right-playing a Dolby Stereo soundtrack over two speakers reproduces the entire encoded soundtrack. There is but one Dolby Stereo movies and Dolby Surround video and television exception: the surround signal, though audible, is not programs include an additional sonic dimension over reproduced in its proper spatial perspective.

  • Page 111: The Dolby Surround Decoder

    channel components in Lt are not identical to the ones in Rt 4. DSP CIRCUIT as a result of a channel balance error, center information will come out of the surround channel in the form of unwanted A surround component (L-R) is extracted from L, R audio crosstalk.
  • Page 112 Fig. 15-3 Block diagram of DSP circuit...
  • Page 113 difference between the direct sound and the reflected sound. As shown in Fig.1 5-4, a sound emitted in a sound field can For more detail, this situation can be expressed with the be classified as a direct sound which directly reaches ears of direct sound, initial reflection sound coming after one time a listener, and reflected sound which comes after collision of reflection, and trains of reverberation sound in later period...

  • Page 114: Dsp (Digital Surround Processor) Ic

    processing is performed by VC, then it feed-backed to the 5. DSP (Digital Surround Processor) IC delay input after it is added to the doubler described above. The output of eight taps T1 to T8 is added after performing Input signal entered into analog input pin 4 of DSP IC QD03 reduction processing by GL1~GL8, GR1~GR8, and reduction (YM7128B) is converted to 14 bit digital signal with the processing is performed by the digital attenuator VL or VR,...
  • Page 115 XD01 CD27 RD32 CD29 CD28 RD33 QD03 REFERENCE TIMING GENERATION LD01 VOLTAGE CD22 GENERATION +B (5V) RD26 From CD21 CD20 DIGITAL DELAY Input LPF CONVERTER T8 T7 T6 T5 T4 T3 T2T1 CD15 CD23 To LPF Output CONVERTER (For FRONT ch) DC26 To LPF Output (For REAR ch)

  • Page 116: Surround Circuit

    6. SURROUND CIRCUIT 7. INPUT BALANCE CIRCUIT The surround circuit used in this model has the modes shown Fig. 15-8 shows the input balance circuit. in Table 15-2 of the modes, description will be given for 5 The input balance circuit is to adjust gain of Lch and Rch so mode.

  • Page 117: Matrix Circuit

    8. MATRIX CIRCUIT 9. FILTER CIRCUIT (ANTI-ALIAS FILTER) Fig.15-9 shows the matrix circuit. The matrix circuit is to create a surround signal of (L-R) from Fig. 15-10 shows the filter circuit. the Lch and Rch signals. According, if a monaural signal The filter circuit is to cut frequencies higher than 7 kHz in enters, L-R=0, showing no surround effect exists.

  • Page 118: Dsp Circuit (Delay)

    10. DSP CIRCUIT (DELAY) Fig.1 5-11 shows the DSP circuit. The DSP circuit delays the surround signal entered by a time of digital delay determined for each mode and then outputs the signal. The DSP circuit is controlled with 3 line-bus data from the sub-microcomputer.

  • Page 119: Khz Low Pass Filter

    11. 7 kHz LOW PASS FILTER The DSP outputs are received at inputs of high impedance voltage followers and then fed to 7 kHz LPFs. Since L and R components of the DSP output are processed in time sharing by the D/A converter, the LO and RO outputs must be received at the high impedance input circuits.

  • Page 120: Dolby Nr Circuit

    12. DOLBY NR CIRCUIT Fig. 15-13 shows the Dolby NR circuit. The Dolby NR circuit used in this unit is a modified B type for Dolby surround and the operation characteristics are shown in Fig. 15-14. RD61 CD43 CD44 CD45 M4700P M0.027 M5600P...

  • Page 121: Dsp Front Addition Circuit

    13. DSP FRONT ADDITION CIRCUIT Fig. 15-15 shows the front addition circuit for the surround signal. In the DSP operation of this model, the surround signal is added to the front channel to provide the surround effect if rear speakers are not used. In practice, the front addition surround signal output from the DSP circuit is added to Lch with the phase non-inverted and to Rch with the phase inverted.

  • Page 122: Bus Converter

    14. BUS CONVERTER 15. NEUTRAL BIAS The bus converter receives I2C-bus data sent from the main To develop a neutral bias voltage for the OP amplifier, +B microcomputer and converts them into DSP control data. (12V) is divided with resistors. The data are transferred to the data input of the DSP.

  • Page 123: Audio Output Amplifier (For Rear Sp)

    16. AUDIO OUTPUT AMPLIFIER (For Rear SP) The audio amplifier develops 5.0W two circuit. C650 C646 1000m35V 100m 25V C641 C647 R640 Ripple Filter 2.2m 50V 1000P 6.8K C652 R660 Rear INPUT 470m 35V 1.5W(5W) R641 1.8K R685 2.2W SURROUND SPEAKER C655 C645...

  • Page 124: Troubleshooting Chart

    17. TROUBLESHOOTING CHART No sound. Check Power supply circuit. Is power supplied +5V, +12V lines? Check A/V SW output. Are input signals applied to 13 , 14 terminals? Check Input Buffer (QD01). Are inputs applied to pins 14 , 8 of QD01? Do output pins L 10 , R 11 develop outputs? Check DSP front addition circuit (QD02).

  • Page 125: Failure Diagnosis Procedures

    SECTION XVI FAILURE DIAGNOSIS PROCEDURES...

  • Page 126: H Starting Circuit Failure Diagnosis Procedures

    1. H STARTING CIRCUIT FAILURE DIAGNOSIS PROCEDURES No raster. Check X-Ray circuit, Check main power voltage. (125V?) protection circuit. Check voltage To "Start circuit diagnosis". at pin 32 of 0501. Check wafeform at pin 23 of IC501. Check and repair H drive circuit, Check and repair C403 H output circuit,...

  • Page 127: Deflection Circuit Failure Diagnosis Procedures

    2. DEFLECTION CIRCUIT FAILURE DIAGNOSIS PROCEDURES No vertical scanning Horizontal one line. Check, repair and replace Check +27V power supply. C310, D302, Q301, R327. Check and repair L462 More than 20V Normal: Check voltage at R313, R304, R305, R306, + leed of C306 R307 in vertical ourput circuit.

  • Page 128: Left-Right Pin-Cushion Distortion Correction Circuit

    3. LEFT-RIGHT PIN-CUSHION DISTORTION CORRECTION CIRCUIT Left-Right pin-cushion distortion correction is not carried out. -27V:NG Check and repair R469 Check voltage across C460 output circuit. on DPC circuit. (-27V) -27V Parabola waveform Check waveform Check and repair around Q461. is not observed at Q461 collector.

  • Page 129: X-Ray Protection Circuit Failure Diagnosis Procedures

    4. X-RAY PROTECTION CIRCUIT FAILURE DIAGNOSIS PROCEDURES X-ray protection circuit does not work (When X - R terminals are connected). Check and repair D471, R472. Check voltage at D471 Check and repair around pin cathode. (20 - 22V?) 9 of FBT. Check and repair Z801.

  • Page 130: Protection Circuit Diagnosis Procedure

    5. PROTECTION CIRCUIT DIAGNOSIS PROCEDURE Operation of protection circuit for Thyrister D862. (SR81 Relay turns on but immediately turns off.) Power on with D870 Check over-current protection circuit, opened. (Do not turn on H output and repair D870, Q870, SR81 turns on for a short time for a long period.) R870 - R873, R876, R881.

  • Page 131: Video Circuit Diagnosis Procedures

    6. VIDEO CIRCUIT DIAGNOSIS PROCEDURES Failure Phenomena Reference Item No picture OSD and picture do not appear. OSD is OK, picture does not appear. OSD is OK, picture does not appear. (A/V circuit is defective.) Picture of only VHF/UHF of main screen does not appear. Picture of only VHF/UHF of sub screen does not appear.
  • Page 132 (A) OSD AND PICTURE DO NOT APPEAR Check R920 (heater resistor) and Check that heater or CRT lights. power/def circuit. Power supply of CRT Drive board. Check power/def circuit. 9V, 200V Check CRT and power/def Check waveform of TP-47R, G, B. circuit.
  • Page 133 (B) OSD IS OK, PICTURE DOES NOT APPEAR Check waveform at pin 53 (Y input) Check I C bus line waveform Check Q501. of Q510. Approx. 0.7V at pins 27, 28 of Q501. Check waveform at pin 4 (Y output) Check C203.
  • Page 134 (B) OSD IS OK, PICTURE DOES NOT APPEAR (A/V CIRCUIT IS DEFECTIVE) Check waveform at pin 36 (Y-AV) Check Q501. Go to (B). or QV01. 2V Check waveform at pin 30 (Y-Comb) or QV01. Check QV01. Check waveform at pin 38 (V-AV) or QV01. Check Comb filter.
  • Page 135 (D) PICTURE OF ONLY VHF/UHF OF MAIN SCREEN Picture of only VHF/UHF of main screen does not appear Check waveform Check waveform at pin 7 Replace QV01 at pin 7 of QV01. of H002. Check/Replace QV40, QV41, QV42, QV43. Check power voltage at pin 4 Check power circuit of H002.
  • Page 136 (E) PICTURE ONLY VHF/UHF OF SUB SCREEN DOES NOT APPEAR(B) OSD IS OK, PICTURE DOES NOT APPEAR Picture of only VHF/UHF of main screen does not appear Check waveform at pin 15 Replace QV01. Check waveform of HY01. at pin 28 of QV01. Check CV09, RV12.
  • Page 137 (F) NO COLOR (AFTER Q501) Check waveform at pin 13 of Q501. Check Q503 and A/V circuit. Burst: 0.3 to 0.6 V Check power supply of Q501. Check power/def circuit. Pin 1=5V, Pins 22, 40, 46=9V Check Q501 and pins 10, 11 Check waveform at pins 5, 6 of Q501.
  • Page 138 (G) NO COLOR (A/V, COMB) Check waveform of video output. Check waveform at pin 32 of QV01. (or check monitor picture.) Burst: 0.3 to 0.6 V Check waveform at pin 34 of QV01. Check comb filter. Check input waveform as noted below. VIDEO 1 pin 14 of QV01 Check QV01.

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