Toshiba TW40F80 manual Memory Circuit Check, No Indication On Screen

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14-4. Memory Circuit Check

Memory circuit check

NG

Voltage check at pin 8 of QA02 (5V).

OK	Check power circuit.

NG

Pulse input at pins 5 and 6 of QA02

in memorizing operation.

OK

Check QA01.

Replace QA02.

Note: Use replacement parts for QA02.

Adjust items of TV set adjustment.

14-5. No Indication On Screen

No indication on screen.

Check of RESET at 5V.

OK

Check of CLK, CS, BUSY, DATA at

pin 22, 23, 24, 25 of QA01.

"H" = 5V or puls?

OK

Check of character signal at pin 59, 60, 61

of QR60 (5V(p-p)).

OK

Check V/C/D circuit.

NG

Replace QA01 or QR60 or QR63.

NG

Replace QA01 or QR60.

NG

Replace QR60.

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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 LogicOn Screen Function EEPROMQA02SDA System Block Diagram Local key assignment Function Local KEY Detection MethodRemote Control Code Assignment Code FunctionTo TV set Custom codes are 40-BFH TV set for North U.S.A Code Function OPT0 OPT1 Models HEX Optional Setting for Each ModelEntering to Service Mode Test Signal SelectionService Adjustment Failure Diagnosis Procedure Contents to be Confirmed by CustomerExecuting Self Diagnosis Function Self Check Understanding Self Diagnosis IndicationClearing method of self diagnosis result Troubleshooting Chart TV does Not Turned onYES 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 MethodSection VI Dual Circuit Outline Principles of OperationScreen multi-search process 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 Section VII 3-DIMENSION Y/C Separator Circuit Outline Configuration Circuit DescriptionCircuit 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~t6Amplitude Correction Linearity Correction LINCurve Correction S Capacitor 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 Regulator1. +210V 2. +35VHigh Voltage High Voltage Circuit CR-BLOCKAnode Actual FBT CR-BLOCK E HED’ 23 X-RAY protection circuit RAY Protection CircuitOver Current Protection Circuit Block Diagram Functions and FeaturesOUT Diode Modulator CircuitActual Circuit Basic Operation and Current Path Later Half Scanning PeriodFirst Half Scanning Period Later Half of Flyback Period First Half of Scanning PeriodP.T Section XI Digital Convergence Circuit Outline Memory ResetProm PLLPicture Adjustment Entering/Exiting Mode Service ModeInitial screen First screen Second screenSfull ENT Key function of remote control unitOperation procedure Each Screen Adjustment MethodNormal/Full Theater Wide1 Theater Wide 269.5 When CRT is Replaced When Convergence Unit is ReplacedCase Study Troubleshooting Adjusting Procedure in Replacing CRTAdjusting Procedure in Replacing Convergence Unit/Main Def Convergence Output Circuit Convergence Block Diagram Convergence Troubleshooting Chart Main Unit