10 CRT/Yoke Assemblies, CRT/Yoke Assemblies Main Function | JVC 250

Chapter 5---Electronics

5.10 CRT/Yoke Assemblies

CRT/Yoke Assemblies - Main Function

!CRTs converts image signal to image light

!Yokes provide horizontal and vertical deflection for CRTs

!Yokes provide x-axis and y-axis convergence correction for CRTs

CRT/Yoke Assemblies - Inputs

To Yokes

H_RGB_YOKE (pos.) - top of red, green, and blue horizontal yokes. V_RGB_YOKE (pos.) - top of red, green, and blue vertical yokes.

RGB_LOCK (pos.) - interlock for red, green, and blue yokes (5 V when closed or 15 V when open).

X_RGB_YOKE (pos.) - top of red, green, and blue X-axis Convergence yokes. Y_RGB_YOKE (pos.) - top of red, green, and blue Y-axis Convergence yokes. To CRTs

Anode Voltage from High Voltage Power Supply (25 kV).

Focus Voltage from High Voltage Power Supply (7 kV).

RGB G1 - G1 grid signal from Video Amplifier PCB.

RGB G2 - G2 supply voltage from Video Amplifier PCB (about 600-800 V).

RGB_CATHODE - video output signal from the Video Amplifier PCB (about 40 Vpp with a peak voltage of about 70 V).

RGB_HEAT (pos.) - positive side of CRTs heater voltage (about 6.2 V).

CRT/Yoke Assemblies - Output

From Yokes

H_RGB_YOKE (neg.) - bottom of red, green, and blue horizontal yokes. V_RGB_YOKE (neg.)- bottom of red, green, and blue vertical yokes.

RGB_LOCK (neg.) - interlock for red, green, and blue yokes (5 V when closed or 0 V when open).

X_RGB_YOKE (neg.) - bottom of red, green, and blue X-axis Convergence yokes.

Y_RGB_YOKE (neg.) - bottom of red, green, and blue Y-axis Convergence yokes.

From CRTs

RGB_HEAT (neg.) - negative side of CRTs heater voltage (0 V).

ARC_GND - CRTs ground (Anode supply return line).

Model 250 Service Manual

5-51

Image 106

JVC 250 10 CRT/Yoke Assemblies, CRT/Yoke Assemblies Main Function, CRT/Yoke Assemblies Inputs, CRT/Yoke Assemblies Output

Contents

Model 250 Projector Declaration of Conformity Manufacturer Hughes JVC Table of Contents Software and Protocol TroubleshootingParts Contents Safety Updates Acronyms Used Secam Contents Introduction Power Supplies Incoming Power CircuitElectrical Section Arc Lamp Module Igniter AssemblyOptical Section Optical Path ILA s Image Light Amplifier CRTs Front Projection Lens Electronic SectionRelay Lens Assemblies Input Cards VICs Printed Circuit Boards PCB Miscellaneous Items EMI Shield System Description Safety Electrical AC Circuit Breaker Incoming Power CircuitAC Power Cord AC EMI Filter Lvps Main Functions Power SuppliesLow Voltage Power Supply Lvps Lvps Inputs 1Low Voltage Power Supply I/O Diagram Lvps Operation Lvps Remove and Replace Arc Lamp Power Supply AlpsLvps Service Adjustments Alps Main Functions Alps Inputs Alps Outputs 2Arc Lamp Power Supply signals and voltages Alps Operation Alps Service Adjustments Alps Remove and Replace High Voltage Power Supply Hvps Hvps Main Functions Hvps Inputs Hvps Outputs Hvps Service Adjustments Hvps Operation 5High Voltage Power Supply cover Hvps Remove and Replace PIN # Electrical Igniter Assembly Outputs Igniter AssemblyIgniter Assembly Inputs Igniter Assembly Operation Igniter Assembly Service Adjustments Igniter Assembly Remove and Replace Electrical Optical Arc Lamp Main Functions Arc Lamp Service AdjustmentsArc Lamp Arc Lamp Inputs Optical 2Arc Lamp alignment fixture 3Arc Lamp Assembly access door Arc Lamp Remove and Replace Optical Optical Path Optical Path Main Function Optical Path Outputs Optical Path InputsOptical Path Operation Optical 6Optical Path Optical Path Service Adjustments 7Optical Path 8XY Positioner adjust holes ILA Inputs ILAILA Main functions ILA Outputs ILA Service Adjustments ILA Operation Optical Optical Optical Optical ILA Remove and Replace Relay Lenses Projection Lens Optical Optical Electronics 1Model 250 System Block Diagram System Controller PCB System Controller PCB Main Function Electronics Electronics 5System Controller PCB I/O Diagram for other PCBs System Controller PCB Inputs System Controller PCB Outputs System Controller PCB Operation Electronics System Controller PCB Remove and Replace Video Processor PCB Main Functions Video Processor PCBVideo Processor PCB Inputs 7Video Processor PCB I/O diagram for VICs and Power Supplies 8Video Processor PCB I/O diagram for PCBs Video Processor PCB Outputs Video Processor PCB Operation 9Video Processor PCB LEDs Video Processor PCB Remove and Replace Raster Timing Generator PCB Raster Timing Generator PCB Main Functions 11Raster Timing Generator for other PCBs Raster Timing Generator PCB Inputs Raster Timing Generator PCB Outputs Raster Timing Generator PCB Operation 12LEDs on the Raster Timing Generator PCB Raster Timing Generator PCB Remove and Replace Horizontal Vertical Deflection PCB Main Functions Horizontal Vertical Deflection PCBHorizontal Vertical Deflection PCB Inputs 13Horizontal/Vertical I/O Diagram Electronics Horizontal Vertical Deflection PCB Outputs Horizontal Vertical Deflection PCB Operation Horizontal Vertical Deflection PCB Service Adjustments 16Red image needs vertical adjustment decrease Electronics Horizontal Vertical Deflection PCB Remove and Replace Convergence Deflection PCBConvergence Deflection PCB Main Functions Convergence Deflection PCB Inputs Convergence Deflection PCB Outputs 19Convergence Deflection PCB I/O Diagram 20Convergence Deflection PCB I/O Diagram 21Physical layout of the Convergence/Deflection PCB Convergence Deflection PCB Operation Convergence Deflection PCB Remove and Replace Scan Reversal PCB Main Functions Scan Reversal PCBScan Reversal PCB Inputs Scan Reversal PCB Outputs 22Scan Reversal PCB I/O Diagram Electronics 24Scan Reversal PCB I/O Diagram for CRT Yokes Scan Reversal PCB Operation Electronics Scan Reversal PCB Service Adjustments Electronics 1Projection orientation jumper settings Scan Reversal PCB Remove and Replace Video Amplifier PCBVideo Amplifier PCB Main Functions Video Amplifier PCB Inputs 26Video Amplifier PCB I/O Diagram Video Amplifier PCB Outputs Video Amplifier PCB Operation Video Amplifier PCB Remove and Replace Electronics 28Video Amplifier PCB showing CRT Socket Connectors CRT/Yoke Assemblies Inputs 10 CRT/Yoke AssembliesCRT/Yoke Assemblies Main Function CRT/Yoke Assemblies Output CRT/Yoke Assemblies Service Adjustments CRT/Yoke Assemblies Operation Electronics Electronics Electronics 30View of CRTs, Relay lenses and ILA Assemblies CRT/Yoke Assemblies Remove and Replace Video Input Cards VICs Standard Rgbhv VIC Rgbhv VIC Main Functions Rgbhv VIC Outputs Rgbhv VIC Service AdjustmentsRgbhv VIC Inputs Rgbhv VIC Operation Graphics Enhancer Plus Rgbhv VIC Grahics Enhancer Plus Rgbhv VIC Main Functions Graphics Enhancer Plus VIC Inputs Graphics Enhancer Plus VIC Outputs Graphics Enhancer Plus VIC Operation Graphics Enhancer Plus VIC Service AdjustmentsGraphics Enhancer Plus VIC Remove and Replace Input Quad Rgbhv VIC Main Functions Input Quad Rgbhv VICInput Quad Rgbhv VIC Inputs 364-Input Quad Rgbhv VIC Input Quad Rgbhv VIC Operation Input Quad Rgbhv VIC Service AdjustmentsInput Quad Rgbhv VIC Outputs Input Quad Rgbhv VIC Remove and Replace YPbPr VIC YPbPr VIC Main Functions YPbPr VIC Outputs YPbPr VIC InputsYPbPr VIC Operation YPbPr VIC Service Adjustments YPbPr VIC Remove and Replace Quad Standard Decoder VIC Quad Standard Decoder VIC Main Functions Quad Standard Decoder VIC Outputs Quad Standard Decoder VIC InputsQuad Standard Decoder VIC Operation Quad Standard Decoder/Line Doubler VIC Quad Standard Decoder VIC Service AdjustmentsQuad Standard Decoder VIC Remove and Replace Electronics 42Backplane Diagram left side Backplane PCB See Figure 44Backplane Diagram right side Electronics Miscellaneous Items Projector Covers Electronics Module Tilt-up Ventilation 1Electronics Module hinge and locking mechanism IR Detectors Air FiltersEMI Filter Cleaning Lenses, ILA Assemblies and Mirrors Miscellaneous Items Troubleshooting LEDs Backpanel LEDs Troubleshooting Troubleshooting Video Processor PCB LEDs Video Processor Test Points Video Processor LEDs Raster Timing Generator PCB LEDs 6Raster Timing Generator LEDs Raster Timing Generator PCB LEDs Convergence Deflection PCB LED Video Amplifier PCB LED Backplane PCB LEDs Diagrams Command on Timing Troubleshooting Image Path Deflection Path Troubleshooting Troubleshooting 14CRT Deflection path between the Scan Reversal PCB and CRT CRT Protection Troubleshooting 16CRT Protection path between the Scan Reversal PCB and CRT Error Codes IIC Handler Troubleshooting Troubleshooting Troubleshooting Guide Problem Check Possible Solution Section Troubleshooting on the Backplane PCB 17Backplane Diagram left side Lamplit Lampok Lampena Coveron GND 19Backplane Diagram right side Troubleshooting Software and Protocol Software Updating Command Software and Protocol Updating Configuration Importing/Exporting Exporting Windows Terminal Transfers + Receive Text File Similar message is displayed on the projector screen Importing Stop, Pause, % complete bar, Sending EXPORT1.TXT Data Transfer Error Example Model 250 Menu will display Null Modem Adapter Terminals Terminals and Communication ProtocolsTerminal Preferences Communications Protocol POS RGB Software and Protocol Software and Protocol Replacement Parts List Description Description Spares Description Quantity Parts List Arc Lamp Cross-member AssemblyAmorphous Aspect Ratio Frame Laser Power SupplyField Horizontal Scan Luminance ResolutionLumen Noise Saturated Color Vertical ResolutionVideo Scan Vertical Synchronization Vertical Scan FrequencyVertical Scan Frequency