Video Processor LEDs | JVC 250 guide

Chapter 7---Troubleshooting

Sync - There are three sync test points: H sync for the horizontal sync pulse, V sync for the vertical sync pulse, and G sync, which is a combination of the horizontal and vertical sync pulses that are carried with the green image signal.

External - There are three external image test points: R ext, for the red external image signal, G ext for the green external image signal, and B ext for the blue external image signal. The external signal is the image signal coming into the Video Processor PCB from the VIC.

Figure 7-5Grey/Pluge (test pattern #7) with associated waveform.

Video - There are three video test points: R video for the red output image signal, G video for the green output image signal, and B video for the blue output image signal. The video signal is the image signal leaving the Video Processor PCB and going to the Video Amplifier PCB.

Ground - The Gnd test point is for reference ground.

The other test point on the Video Processor PCB is for the /Clamp signal, which is not very useful for troubleshooting purposes.

Video Processor - LEDs

The Video Processor PCB has two green LEDs. VP_OK is a status line that indicates that the Video Processor PCB is has power (±15 V). The Beam current LED will be illuminated orange if any of the CRTs is at or exceeding beam current limit (250 µA). If any of the CRTs is at the beam current limit, the Video Processor will reduce Contrast. If reducing Contrast does not bring down the beam current for that CRT, the Video Processor PCB will reduce G2 voltage.

7-6	Model 250 Service Manual

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JVC 250 service manual Video Processor LEDs

Contents

Model 250 Projector Declaration of Conformity Manufacturer Hughes JVC Table of Contents Troubleshooting Software and ProtocolParts Contents Safety Updates Acronyms Used Secam Contents Introduction Incoming Power Circuit Power SuppliesElectrical Section Igniter Assembly Optical SectionArc Lamp Module Optical Path ILA s Image Light Amplifier CRTs Electronic Section Relay Lens AssembliesFront Projection Lens Input Cards VICs Printed Circuit Boards PCB Miscellaneous Items EMI Shield System Description Safety Electrical Incoming Power Circuit AC Power CordAC Circuit Breaker AC EMI Filter Power Supplies Low Voltage Power Supply LvpsLvps Main Functions Lvps Inputs 1Low Voltage Power Supply I/O Diagram Lvps Operation Arc Lamp Power Supply Alps Lvps Service AdjustmentsLvps Remove and Replace 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 Igniter Assembly InputsIgniter Assembly Outputs Igniter Assembly Operation Igniter Assembly Service Adjustments Igniter Assembly Remove and Replace Electrical Optical Arc Lamp Service Adjustments Arc LampArc Lamp Main Functions 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 Inputs Optical Path OutputsOptical Path Operation Optical 6Optical Path Optical Path Service Adjustments 7Optical Path 8XY Positioner adjust holes ILA ILA Main functionsILA Inputs 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 Video Processor PCB Main FunctionsVideo 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 Horizontal Vertical Deflection PCB Main FunctionsHorizontal 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 Convergence Deflection PCB Horizontal Vertical Deflection PCB Remove and ReplaceConvergence 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 Scan Reversal PCB Main FunctionsScan 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 Video Amplifier PCB Scan Reversal PCB Remove and ReplaceVideo 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 10 CRT/Yoke Assemblies CRT/Yoke Assemblies Main FunctionCRT/Yoke Assemblies Inputs 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 Service Adjustments Rgbhv VIC InputsRgbhv VIC Outputs 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 Service Adjustments Graphics Enhancer Plus VIC OperationGraphics Enhancer Plus VIC Remove and Replace Input Quad Rgbhv VIC Input Quad Rgbhv VIC Main FunctionsInput Quad Rgbhv VIC Inputs 364-Input Quad Rgbhv VIC Input Quad Rgbhv VIC Service Adjustments Input Quad Rgbhv VIC OutputsInput Quad Rgbhv VIC Operation Input Quad Rgbhv VIC Remove and Replace YPbPr VIC YPbPr VIC Main Functions YPbPr VIC Inputs YPbPr VIC OutputsYPbPr 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 Inputs Quad Standard Decoder VIC OutputsQuad Standard Decoder VIC Operation Quad Standard Decoder VIC Service Adjustments Quad Standard Decoder/Line Doubler VICQuad 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 Air Filters IR DetectorsEMI 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 and Communication Protocols TerminalsTerminal Preferences Communications Protocol POS RGB Software and Protocol Software and Protocol Replacement Parts List Description Description Spares Description Quantity Parts List Cross-member Assembly AmorphousArc Lamp Aspect Ratio Laser Power Supply FieldFrame Horizontal Scan Resolution LumenLuminance Noise Vertical Resolution VideoSaturated Color Scan Vertical Scan Frequency Vertical ScanVertical Synchronization Frequency