Tektronix 071-1143-01

Remove and Replace

WFM90D and WFM91D ServiceManual 6-23

Backlight

board

Figure6 -10: Removing the Backlight board

Contents

Main Page WARRANTY Page Table of Contents Specifications Operating Information Theory of Operation Performance Verification Adjustment Procedures Adjustments 5--1.............................................. Adjustment Procedures:Analog Section 5--5....................... Adjustment Procedures:Digital Section 5--11....................... Maintenance Page List of Figures Page List of Tables General Safety Summary Symbolsand Terms Service Safety Summary Page Preface About This Manual Related Manuals Preface xii WFM90D and WFM91D ServiceManual Contacting Tektronix Page Page Specifications Product Description Key Features CharacteristicsTables ElectricalSpecifications WFM90D and WFM91D ServiceManual 1-3 Table1- 1: Verticaldeflection system (Cont.) 1-4 WFM90D and WFM91D Service Manual Table1- 1: Verticaldeflection system (Cont.) Table1- 2: DCr estoration WFM90D and WFM91D ServiceManual 1-5 Table1- 3: Audiomode Table1- 4: Horizontal deflection system 1-6 WFM90D and WFM91D Service Manual Table1- 5: Vectormode WFM90D and WFM91D ServiceManual 1-7 Table1- 6: Synchronization Table1- 7: Powersource 1-8 WFM90D and WFM91D Service Manual Physical Characteristics Table1- 8: Physicalcharacteristics EnvironmentalCharacteristics Table1- 9: Environmental characteristics WFM90D and WFM91D ServiceManual 1-9 Certification and Comp liances Table1- 10: Certifications and Compliances 1-10 WFM90D and WFM91D Service Manual Table1- 10: Certifications and Compliances (Cont.) Page Page Installation Mechanical Installation Unpacking ViewingHood Page TravelCase ElectricalInstallation Instrument Configuration Power Source Recharging the NiMH Replacing the NiMH Replacing the Alkaline Page Functional Overview Keypad Controls Display Mode Selection Power Switch Page Menu Control Arrow Buttons Side-Panel Connectors and Switches Instrument Reset Page Onscreen Readouts Readout Description Page Page Using the Menus 2-16 WFM90D and WFM91D Service Manual Figure2 -10: Audio, Picture, and Waveform -in-Picture menus Figure2 -11: Line Select menu Operating Menus Accessing Menus Accessing Digital Menus Using the Menus WaveformMenu VectorMenu Audio Menu Picture Menu WIP Menu (Waveform-in-Picture) ConfigurationMenu Configuration Menu Access Using the Configuration Menu 2-22 WFM90D and WFM91D Service Manual Figure2 - 12: Configurat ion menu WFM90D and WFM91D ServiceManual 2-23 Table2- 7: Configure menu choices 2-24 WFM90D and WFM91D Service Manual Table2- 7: Configure menu choices (Cont.) WFM90D and WFM91D ServiceManual 2-25 Table2- 8: Default instrument settings Line Select Menu Page Page Theory of Operation Input Board SDI Interface Board Top Board Bottom Board LCD Display and Backlight(Serial Numbers B020100 and Above) LCD Display and Backlight(Serial Numbers Below B020100) Theory of Operation WFM90D and WFM91D ServiceManual 3-3 InputBoard Figure3 -1: Simplified block diagram (serial numbers B020100 and above) Bottom Board Theory of Operation 3-4 WFM90D and WFM91D Service Manual InputBoard Figure3 -2: Simplified block diagram (serial numbers below B020100) Bottom Board Page Page Performance Verification Conventions Summary Verification Prerequisites Page Performance Verification 4-4 WFM90D and WFM91D Service Manual Table4- 2: Equipment required for performance verification (Cont.) Performance Verification: Analog Section Sync Separation Sweep Timing and IntegralLinearity VerticalGain and Vertical Magnifier Registration VariableGain Range and Vertical Position Range Overscan Input and DC Restorer Frequency Response Page VectorPhase Stability Chrominance Bandwidth Audio Gain and Frequency Response Page Performance Verification: Digital Section Check Sync Separation Check Frequency Response Check Frequency Response at X5 Gain Page Page Page Adjustments Summary Adjustment Adjustments 5-2 WFM90D and WFM91D Service Manual Adjustment Procedures Conventions Prerequisites How to Adjust Instrument Settings Page Adjustment Procedures: Analog Section Raster VCO Sweep Timing and HorizontalMag Registration Page VerticalGain and X5 Gain Registration Frequency Response Page VectorQuadrature Phase VectorGain and X5 Gain Phase Audio Gain Adjustment Procedures: Digital Section VerticalGain Frequency Response VectorGain and X5 Gain Phase Cable Margin Page Page Page Maintenance Cleaning General Care Cleaning the Exterior Interior VisualInspection After Repair Adjustments Repackaging Instructions Performance Verification and Adjustments Remove and Replace ToolsRequired Remove and Replace 6-4 WFM90D and WFM91D Service Manual Procedures Top Cover Assembly TopCover LCD Display Lens Page LCD Display Assembly LCD - Newer Instruments Page Page LCD - Older Instruments Page Page Backlight Top BoardAssembly TopBoard Keypad TopBoard Shield Page Bottom Board Page SDI Interface Board Backlight Board Page Input Board Assembly Battery Cover Assembly Battery Cover Carrying Strap Page Page Batteries Battery Cushion Pad NiMHBattery Pack AlkalineB atteries Page Bottom Cover Assembly Bottom Cover Battery Power Connector Battery Contacts Page TurnlockStud Receptacle Bottom Cover Electrical Shield Page Page AC Adapter EMI Suppressor Page Troubleshooting Procedures Battery-FaultAnalysis + -- Page Low-VoltagePower Supply Fault Symptom Table TroubleshootingFlowcharts WFM90D and WFM91D ServiceManual 6-45 No Figure6 -20: Flowchart for no display 6-46 WFM90D and WFM91D Service Manual Figure6 -21: Flowchart for distorted waveform display WFM90D and WFM91D ServiceManual 6-47 Figure6 -22: Flowchart for no vector display 6-48 WFM90D and WFM91D Service Manual Figure6 -23: Flowchart for problems processing serial digital input signals WFM90D and WFM91D ServiceManual 6-49 Figure6 -24: Flowchart for bad audio display 6-50 WFM90D and WFM91D Service Manual Figure6 -25: Flowchart for no picture display WFM90D and WFM91D ServiceManual 6-51 Figure6 -26: Flowchart for bad grat iculesand m enus 6-52 WFM90D and WFM91D Service Manual Figure6 -27: Flowchart for all white display WFM90D and WFM91D ServiceManual 6-53 No Figure6 -28: Flowchart for untriggered waveform display 6-54 WFM90D and WFM91D Service Manual Figure6 -29: Flowchart for unlocked vector display WFM90D and WFM91D ServiceManual 6-55 Figure6 -30: Flowchart for vector display jitter Figure6 -31: Flowchart for distorted vectors 6-56 WFM90D and WFM91D Service Manual Figure6 -32: Flowchart for problems with the instr ument controls WFM90D and WFM91D ServiceManual 6-57 Figure6 -33: Flowchart for bad menus in the pictur e display Page Connector Diagram Page Page Page Options Options Accessories Page Page Replaceable Parts List Parts OrderingInformation Module Servicing Using the Replaceable PartsList Abbreviations Mfr.Code to Manuf acturer Cross Index Instrument Accessories WFM90D and WFM91D ServiceManual 8-3 Manufacturers Cross Index Mfr. Code Manufacturer Address City,State, Z ip Code 8-4 WFM90D and WFM91D Service Manual Figure8 -1: Exploded view (serial numbers B020100 and above) WFM90D and WFM91D ServiceManual 8-5 ReplaceableParts List for serialnumber s B020100 andabove Number Discontd Qty Name& Description Mfr.Code Mfr.Part Number 8-6 WFM90D and WFM91D Service Manual ReplaceableParts List for serialnumber s B020100 and above (Cont.) Discontd Number Mfr.Part NumberMfr.CodeName& DescriptionQty WFM90D and WFM91D ServiceManual 8-7 A5 Figure8 -2: Exploded view (serial number s below B020100) 8-8 WFM90D and WFM91D Service Manual ReplaceableParts List for serialnumber s belowB020100 Number Discontd Qty Name& Description Mfr.Code Mfr.Part Number WFM90D and WFM91D ServiceManual 8-9 ReplaceableParts List for serialnumber s belowB020100 (Cont.) Discontd Number Mfr.Part NumberMfr.CodeName& DescriptionQty 8-10 WFM90D and WFM91D Service Manual ReplaceableParts List for serialnumber s belowB020100 (Cont.) Page Page WFM90D and WFM91D ServiceManual 9-1 Diagrams Figure9 -1: Interconnect diagram f or instruments with serial numbers B020100 and above Diagrams Figure9 -2: Interconnect diagram f or instruments with serial numbers below B020100 9-2 WFM90D and WFM91D Service Manual