Toshiba TW40F80 manual Convergence Output Circuit

Page 98

6. CONVERGENCE OUTPUT CIRCUIT

6-1. Outline

This circuit current-amplifies digital convergence correction signal at output circuit, and drives by convergence yoke to perform picture adjustment.

Digital convergence output signal 6ch adjustment is done.

(H-R/G/B) (V-R/G/B)

6-2. Circuit Description

6-2-1. Signal flow

Signal which is corrected by digital convergence, is output to P708 (V, H R/G/B);

is input to Q751 (V) R/G/B, and is output to P713, P714 and P715;

is input to Q752 (H) R/G/B, and is output to P713, P714 and P715.

6-2-2. Over current protection circuit

All currents of Power supply, -15V, +15V and +30V are de- tected to protect CONV-OUT IC from damage due to output short of CONV-OUT.

Current value: Normal ± 15V approx. 700mA

+30V approx. 200mA

Detecting curren ±15V approx. 1.8A or more

+30V approx. 700mA or more protecting operation

6-2-4. CONV-OUT mute

In power-on operation, transistors Q765 and Q766 are made turned ON, and –15V is applied to pin 3 of CONV-OUT IC. These cause mute operation on CONV-OUT.

6-2-5. Operation of IC

1) Q764 (TC74HC4050AP)

Sync signal which is input from P711 1 VD, 2 HD, is, through buffer, supplied to digital convergence P708.

2) 3-terminal source

Q754 (+5V) Q755 (+9V) Q756 (-9V)

Source for digital convergence

3) Q767 (TC4066BP)

P711 4 SDAM, 5 SCLM : microcomputer. Busline, through Q767, is input to Digital Convergence P709, and is controlled.

4) To adjust from outside of digital convergence :

Put adjusting jig into 6P socket of P720. Iscs turns from H to L, switch of Q767 is changed over. Then busline from mi- crocomputer is cut off.

P720 3 SCLU, 4 SDAU

Controlled by external adjusting jig.

6-2-3. Pump-up source

CONV-OUT IC Q752 (H)

Pin 10 (+15V/H, PV)

Pin 5 (+30V)

By HD input signal, pump-up is done only in horizontal re- tracing time.

		Pump-up
		Pump-up source waveform
	Horizontal correction wafeform
	+30V	+30V
	+30V
	+15V	+15V
	+15V	0V
		0V
	0V	-15V
		-15V
	-15V
		Horizontal correction waveform

Fig. 11-13

98

Image 98

Contents TW40F80 Contents Terminal FUNCTION, Description and Block Diagram Wide Aspect Conversion Circuit Failure AnalysisSection X Deflection Distortion Correction Circuit Section XI Digital Convergence CircuitOutline Merits of BUS System Section FeatureImproved Serviceability Reduction of Parts CountSpecifications Chassis ModelFront View Video 3 InputsRear View IN-VIDEORemote Control View 100Chassis Layout Starsight Newosd FRO. SurrConstruction of Chassis Outline Major FeaturesSection II TUNER, IF/MTS/S. PRO Module Circuit Block RF AGCAudio Multiplex Demodulation Circuit A.PRO block diagram A.PRO Section Audio ProcessorConfiguration of the audio circuit and signal flow are given POP Tuner Terminal No NameOperation of Channel Selection Circuit Microcomputer SDA SCLMicrocomputer Terminal Function Microcomputer Terminal Name and Operation Logic Terminal Name Function In/Out Logic RemarksSDA On Screen FunctionEEPROMQA02 System Block Diagram Local KEY Detection Method Local key assignment FunctionTo TV set Remote Control Code AssignmentCode Function Custom codes are 40-BFH TV set for North U.S.A Code Function Optional Setting for Each Model OPT0 OPT1 Models HEXService Adjustment Entering to Service ModeTest Signal Selection Executing Self Diagnosis Function Failure Diagnosis ProcedureContents to be Confirmed by Customer Understanding Self Diagnosis Indication Self CheckClearing method of self diagnosis result YES Troubleshooting ChartTV does Not Turned on No Acception of KEY-IN No Picture Snow NoiseMemory Circuit Check No Indication On ScreenSection IV DVD Switch Circuit DVD Switch Block Diagram Outline Circuit Operation ConfigurationSection V WAC Circuit Outline OperationWide aspect conversion unit block diagram PB6348 Pin Function Pin function of TC9097F QFP 80 pinNames and functions of TC9097F Name FunctionVFL2 Block Diagram TC9097F system block diagramWide Aspect Conversion Circuit Failure Analysis Procedures E2PROM OK?Adjustment Method Raster Horizontal OneScreen multi-search process Section VI Dual Circuit OutlinePrinciples of Operation System Component Diagram of Dual Unit Video/Color/Deflection Process Section OSD Sub Screen Process Section Sub screen process sectionMain/Sub Screen Superimposing Section Main/Sub screen superimposing sectionQY01 Main IC Terminal FUNCTION, Description and Block DiagramDiagram MPC1832GTQY01 mPC1832GT pin layout QY03 TC9092AF internal block diagram QY03 TC9092AF pin layout QY03 TC9092AF pin list No Pin name Pin function CKWMRD1 QY10/QY11 M518221-30ZS internal block diagram Circuit Description Section VII 3-DIMENSION Y/C Separator Circuit OutlineConfiguration Circuit Description Terminal description PZ01 Section Viii Vertical Output Circuit Outline Theory of OperationSawtooth Waveform Generation Output CircuitActual Circuit Circuit OperationOutput Output stage power supply voltage Character Correction Up-and Down-ward Extension Correction Linearity Characteristic CorrectionProtection Circuit for V Deflection Stop Up-and Down-ward Linearity BalanceUZ22BSD +35V Over Current Protection CircuitTheory of Operation UZ11BSBRaster Position Switching Circuit KetsuHorizontal Drive Circuit SignalSection IX Horizontal Deflection Circuit Outline Basic Operation of Horizontal DriveOn period OFF period Operation of Basic Circuit Signal DEF/POWER PCBHorizontal Output Circuit FBTT3~t4 Description of the basic circuit T1~t2T2~t3 T4~t6Curve Correction S Capacitor Amplitude CorrectionLinearity Correction LIN Left-right Asymmetrical Correction LIN coil Linearity coilOperation Theory White Peak Bending Correction CircuitOutline EHTBlanking Low Voltage Protection Gate ProtectorABL High Voltage Generation CircuitAFC High Voltage DPC Circuit RegulatorHigh Voltage 1. +210V2. +35V Anode High Voltage CircuitCR-BLOCK ED’ ActualFBT CR-BLOCK E H RAY Protection Circuit 23 X-RAY protection circuitOver Current Protection Circuit Functions and Features Block DiagramDiode Modulator Circuit OUTActual Circuit First Half Scanning Period Basic Operation and Current PathLater Half Scanning Period P.T Later Half of Flyback PeriodFirst Half of Scanning Period Section XI Digital Convergence Circuit Outline Prom ResetMemory PLLPicture Adjustment Service Mode Entering/Exiting ModeSfull Initial screenFirst screen Second screen Key function of remote control unit ENTNormal/Full Operation procedureEach Screen Adjustment Method Theater Wide1 Theater Wide 269.5 Case Study When CRT is ReplacedWhen Convergence Unit is Replaced Adjusting Procedure in Replacing Convergence Unit/Main Def TroubleshootingAdjusting Procedure in Replacing CRT Convergence Output Circuit Convergence Block Diagram Convergence Troubleshooting Chart Main Unit