Toshiba TW40F80 manual Raster Position Switching Circuit, Ketsu

Page 65

4. RASTER POSITION SWITCHING CIRCUIT

4-1. Outline

So, adjust the center of the picture to the center of the screen

When the vertical screen position adjustment is carried out

in advance under the output V sync delayed.

 

on the projection TV, DC current is directly flown in the

To do this, lower the raster position by flowing a DC current

vertical deflection yoke and the raster cannot be moved up

to the deflection yoke in the CINEMA and SUBTITLE

and down. (Because the raster is moved, the color distortion

mode.

may occur.) Accordingly, the vertical screen position

The operation above is carried out by the vertical screen

adjustment is carried out by the following method. (Only in

position SW circuit.

CINEMA and SUBTITLE mode)

 

V sync pulse output from Q501 sync. separation circuit is

4-2. Operation

once input to WAC, delayed and then output. The deflection

circuit operates with the delayed sync signal. The screen

When CINEMA and SUBTITLE are selected in the screen

 

upper side position moves up and down by varying the delay

mode, a zoom signal is input to the base of Q362 from the

 

time. When the vertical position adjustment is carried out

autolive circuit and Q362 turns on. Then, Q363 turns off

 

by WAC, the followings must be considered.

and the base of Q364 develops H and Q364 turns on. The

 

WAC becomes “through” except for CINEMA and

inverted DC current flows into the vertical deflection yoke

SUBTITLE mode.

from +35V power supply line.

The phase of the output V sync must not advance from that of WAC input V sync. If it advances, Vertical jitter may occur when performing the search operation and the vertical position adjustment of a VTR.

 

 

 

R363

R364

 

 

 

 

 

R362

2R

KETSU

R365

 

 

Fig. 8-12

R360

220

 

R366

 

33K

1R5.6K

 

 

1R5.6K

33K

 

 

 

Q364

 

 

 

 

 

 

Q362

R361 2SC2023

 

 

R367

Q366

 

12K

 

 

 

12K

 

RN1204

 

 

 

RN1204

 

 

 

 

 

 

 

 

Q363

 

Q367

 

 

 

 

 

 

2SC2023

Q365

 

 

 

 

2SC1815Y

 

 

 

 

 

 

 

 

2SC1815Y

 

 

 

 

 

 

 

 

 

 

D361

 

 

 

 

 

 

 

S5965G

 

 

 

 

 

 

+35V

 

 

 

 

 

 

 

+12V

 

 

 

 

 

 

P360

 

 

 

 

 

 

Fig. 8-13

Screen

mask

position

Nomal mode (4:3, Full, Dramatic Wide)

 

Screen

Raster position

mask

position

 

Mode in which the opposite current flows into D Y (Cinema)

65

Page 64 Page 66
Image 65
Page 64 Page 66
Contents TW40F80 Contents Wide Aspect Conversion Circuit Failure Analysis Terminal FUNCTION, Description and Block DiagramSection XI Digital Convergence Circuit Section X Deflection Distortion Correction CircuitImproved Serviceability Section FeatureOutline Merits of BUS System Reduction of Parts CountChassis Model SpecificationsVideo 3 Inputs Front ViewIN-VIDEO Rear View100 Remote Control ViewStarsight Newosd FRO. Surr Chassis LayoutConstruction of Chassis Section II TUNER, IF/MTS/S. PRO Module Circuit Block Major FeaturesOutline RF AGCAudio Multiplex Demodulation Circuit A.PRO Section Audio Processor A.PRO block diagramConfiguration of the audio circuit and signal flow are given Terminal No Name POP TunerOperation of Channel Selection Circuit SDA SCL MicrocomputerMicrocomputer Terminal Function Terminal Name Function In/Out Logic Remarks Microcomputer Terminal Name and Operation LogicSDA On Screen FunctionEEPROMQA02 System Block Diagram Local key assignment Function Local KEY Detection MethodTo TV set Remote Control Code AssignmentCode Function Custom codes are 40-BFH TV set for North U.S.A Code Function OPT0 OPT1 Models HEX Optional Setting for Each ModelService Adjustment Entering to Service ModeTest Signal Selection Executing Self Diagnosis Function Failure Diagnosis ProcedureContents to be Confirmed by Customer Self Check Understanding Self Diagnosis IndicationClearing method of self diagnosis result YES Troubleshooting ChartTV does Not Turned on No Picture Snow Noise No Acception of KEY-INNo Indication On Screen Memory Circuit CheckSection IV DVD Switch Circuit DVD Switch Block Diagram Outline Section V WAC Circuit Outline ConfigurationCircuit Operation OperationWide aspect conversion unit block diagram PB6348 Pin function of TC9097F QFP 80 pin Pin FunctionName Function Names and functions of TC9097FVFL2 TC9097F system block diagram Block DiagramE2PROM OK? Wide Aspect Conversion Circuit Failure Analysis ProceduresRaster Horizontal One Adjustment MethodScreen 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 SectionDiagram Main IC Terminal FUNCTION, Description and Block DiagramQY01 MPC1832GTQY01 mPC1832GT pin layout QY03 TC9092AF internal block diagram QY03 TC9092AF pin layout CKW QY03 TC9092AF pin list No Pin name Pin functionMRD1 QY10/QY11 M518221-30ZS internal block diagram Circuit Description Section VII 3-DIMENSION Y/C Separator Circuit OutlineConfiguration Circuit Description Terminal description PZ01 Theory of Operation Section Viii Vertical Output Circuit OutlineActual Circuit Output CircuitSawtooth Waveform Generation Circuit OperationOutput Output stage power supply voltage Protection Circuit for V Deflection Stop Linearity Characteristic CorrectionCharacter Correction Up-and Down-ward Extension Correction Up-and Down-ward Linearity BalanceTheory of Operation +35V Over Current Protection CircuitUZ22BSD UZ11BSBKetsu Raster Position Switching CircuitSection IX Horizontal Deflection Circuit Outline SignalHorizontal Drive Circuit Basic Operation of Horizontal DriveOn period OFF period Horizontal Output Circuit Signal DEF/POWER PCBOperation of Basic Circuit FBTT2~t3 Description of the basic circuit T1~t2T3~t4 T4~t6Curve Correction S Capacitor Amplitude CorrectionLinearity Correction LIN Linearity coil Left-right Asymmetrical Correction LIN coilOutline White Peak Bending Correction CircuitOperation Theory EHTBlanking Gate Protector Low Voltage ProtectionAFC High Voltage Generation CircuitABL High Voltage DPC Circuit RegulatorHigh Voltage 1. +210V2. +35V Anode High Voltage CircuitCR-BLOCK ED’ ActualFBT CR-BLOCK E H 23 X-RAY protection circuit RAY Protection CircuitOver Current Protection Circuit Block Diagram Functions and FeaturesOUT Diode Modulator CircuitActual 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 Memory ResetProm PLLPicture Adjustment Entering/Exiting Mode Service ModeSfull Initial screenFirst screen Second screen ENT Key function of remote control unitNormal/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
Top Page Image Contents