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JVC 370 SC, 330, 340 SC service manual High Voltage Power Supply HVPS

Models: 340 SC 370 SC 330

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4.10High Voltage Power Supply (HVPS)

Chapter 4—Maintenance

7.Perform a CRT mechanical focus adjustment (Section 3.7) and yoke alignment (Section 3.2) after yoke replacement.

4.10High Voltage Power Supply (HVPS)

The HVPS is located on the left side of the projector next to the CRT housing assembly.

To remove the HVPS:

1.Unplug the projector. Wait at least a minute before proceeding for the high voltage to bleed off.

2.Run all three (3) CRTs all the way forward using the Z axis focus rods at the rear of the CRT assembly (Photo 4-6).

3.Remove all three (3) video amplifier boards (refer to Section 4.8 and either Figure 4-4 or Figure 4-5).

4.Remove the System Power Supply (see Section 4.5).

5.Remove the System Power Supply mounting plate (covers High Voltage Power Supply).

6.Inside the CRT housing on the left side, disconnect all three (3) CRT anode cables from the bulkhead connectors. As an added precaution, short the anode leads to the High Voltage Chassis ground to bleed off any residual charges. Slide the anode wire connectors off their mounting brackets.

7.In the bottom rear of the CRT housing, cut the tie wraps holding the HV, G2, and focus cables.

8.Carefully slide all G2, and focus cables out of the CRT housing.

9.Remove the top connector (power control) at the rear of the HVPS.

10.Loosen and release the five (5) captive screws at the base of the HVPS: Two (2) screws are located forward.

One (1) screw on top. Two (2) screws at the rear.

11.Remove the HVPS.

12.Replace the HVPS in the reverse order.

13.Perform a CRT mechanical focus adjustment, yoke alignment, G2 adjustment, and electronic focus adjustment after HVPS replacement (Sections 3.7, 3.2, 3.10, and 3.8).

NOTE: When replacing the HVPS, ensure that the wires are routed to the proper color and that the wires are neatly placed in the bottom of the CRT housing.

4-20	Model 330. 340SC, 370SC Service Manual

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JVC 370 SC, 330, 340 SC service manual High Voltage Power Supply HVPS

Contents

Hughes-JVC Technology Corporation DECLARATION OF CONFORMITYSERVICE MANUAL Model Model 340 SC Model 370 SCConfidential and proprietary information Manufacturer Hughes-JVC Technology CorporationSafety Equipment Safety InformationIntroduction Warnings and CautionsProjector Weight Installation SafeguardsLight Safeguards Heat SafeguardsFans Ultra Violet and Infrared LightUltraviolet radiation, dangerous glare, and high internal gas pressure Power Supply Fluid SafeguardsVentilation and Foreign Object Retrieval PowerModel 330, 340SC, and 370SC Service Manual SafetyModel 330, 340SC, and 370SC Service Manual Safety1.1 Acronyms Used In Manual 1.0 Introduction1.3 Updates 1.2 Safety1.4 Hardware Compatibility Model 330, 340SC and 370SC Service ManualVideo Amplifier Board 2.0 Functional Descriptions Contents2.1 Cover and Base 2.3 Electronics Systems Overview 2.2 External Power RequirementsThe Model 330, 340SC and 370SC Electronics System consists of System Power Supply 2.4 System PowerFigure 2-2 Backplane Status Indicators ∇ Model 330. Model 340SC = +25V/80a Model 370SC = +30V/100a 2. +24V Standby and Arc Lamp power supplies turn on Arc Lamp Ignitor 22-30V depending on projector model High Voltage Power Supply Power and Control Connector High Voltage Power SupplyModel 330, 340SC, and 370SC Service Manual Pins 1,4,5,10 not usedCRT anode voltages are not user controllable. They are fixed at 32KV with a maximum output of 2.1mA total or 0.7mA per CRT. The anode voltage is the primary acceleration voltage for the CRT. Other bias voltages screen grid, G2, and control grid, G1 are used to control the level of beam current. The anode voltage is routed out of the top of the HVPS, into the CRT housing to three 3 bulkhead connectors. From there, the anode wires on the CRTs route the anode voltage directly to the CRT. The anode voltages are overvoltage and overcurrent protected in the event of short circuits or CRT arcing 2.5 Card Cage Description 2.6 Circuit Boards340SC 370SCChapter 2-Functional Descriptions Model 330, 340SC, and 370SC Service Manual2-16 Model 330, 340SC and 370SC Service Manual Figure 2-10 Raster Generation Block DiagramChapter 2-Functional Description 2-17Raster Timing Generator Board RTG p/n Sync Detector and Selector Sync GeneratorSerration and Equalization Lockout Phase Locked LoopVSYNC Detector, Field Separator, and Mux Adjustment Counters Information Serial CommunicationDescription IICCLK Raster Timing Generator I/OHorizontal Deflection Board Horizontal Deflection Board P/N 102523 HDB Interlocks and ProtectionSystem Power Supply InputsVertical Oscillator Horizontal Power Supply Horizontal Phase Locked LoopHorizontal Centering Geometric Correction Flyback SwitchingOutput Section Serial Communication Horizontal Sweep Failure DetectionInformation DescriptionHorizontal Deflection Board I/O Raster Timing Generator System Power Supply Vertical Deflection Board P/N 102521VDBInterlocks and Protection InputsVertical raster centering Top and bottom pincushion correction Vertical Preamps Sweep Failure Detection Vertical AmplifiersSide Pincushion and Keystone Correction Top and Bottom Pincushion and Keystone Correction Horizontal Linearity CorrectionSerial Communication Correction AmplifiersRXCORR RYCORR GXCORR GYCORR BXCORR Information General I/ODescription System Controller BoardSystem Controller Board Outputs Input Interlocks and ShutdownsOutput InternalChapter 2-Functional Descriptions Model 330, 340SC and 370SC Service Manual2-42 Video Processor Board P/N 104672 VPB Decoder V & H Sync Strip Video/Sync MuxSG Sync Strip B, G, and R Brightness and Contrast AmplifiersSwitch Logic and Video Enable On-Screen SwitchGamma Correction RGB Sensitivity and Threshold Amplifier Dynamic Focus Amplifier ILA BiasSerial Communication InformationSystem Controller Board General I/OInput DescriptionOutputs System Controller BoardDescription Raster Timing GeneratorVertical Deflection Board Outputs Image Light AmplifiersDescription DecoderSystem Power Supply High Voltage Power SupplyInterlocks and Protection OutputsOutput Video Amplifier Board P/N 103567 or 103774 VABInternal Failure Detection Video SignalEnable Circuit DC RestoreBeam Current Sense Arc ProtectionGeneral I/O This section provides a comprehensive description of the inputs to and outputs from the VAB. The I/O description are arranged by the source/destination of the signal and so the assemblies communicated with are used as the primary heading of each group of signals and then are further subdivided into inputs and outputs. In each case, the signals direction is noted, with input referring to an input to the VAB, and output to an output from the VAB e.g. under Video Processor Board Input CLAMP refers to the signal CLAMP that is an input to the VAB from the Video Processor Board. When test points are provided for the I/O they are notedVideo Processor Board System Power Supply System Controller Board P/N 104668 SCBInputs DescriptionGeneral Functional Description Page Expanded Memory Working and Compressed MemoryDACs Correction Address GeneratorOverlay Address Generator Overlay MemoryLED Display Buffers and Logic Overlay InterfaceRS232 Interface IR InterfaceSerial Interface IIC InterfaceThere are three 3 ports for receiving IR radiation. One 1 is located on the front of the projector just above the Green projection lens and the other two 2 are located on the rear panel. One of the receivers on the rear panel is located next to the LED display and, like the front receiver, is used for directly receiving IR radiation. The other rear-mounted receiver is used for connecting an IR repeater, which is an optional device that allows the user to control the projector from up to 150 feet away General I/ODescription Video Processor BoardInput DescriptionDescription Raster Timing GeneratorInput DescriptionDescription Vertical Deflection BoardInput DescriptionHorizontal Deflection Board Backplane Board p/n BackplaneImage Light Amplifier ILA Assembly CRT Assembly2.7 Optical Section Relay Lenslight. The vertically polarized light then passes through the prism to the projector lens. The ILA assembly combines the input signal from the CRT with the high intensity light from the arc lamp. Thus, the brightness of the screen image does not depend on the brightness of the CRT but on the light from the xenon arc lamp. A more detailed explanation of the ILA assembly is in Section 2.8 at the end of this chapter Combined Image and High CRT ImageIntensity Light=Bright Image ScreenPrism Arc Lamp AssemblyProjection Lens Optical Subassemblies 2.8 Image Light AmplifierFigure 2-20 The Hughes-JVC Image Light Amplifier Figure 2-21 Simplified illustration of the Series 300 Projector optical path 3.1 Service Cover-Off Power-On Sequence 3.0 Service AdjustmentsContents Chapter 3---Service AdjustmentsMain AC Circuit Breaker 3.2 CRT Yoke Rotation 7. View R 3.3 Vertical Size Tracking 3.4 Vertical Linearity Tracking 3.5 Horizontal Size Tracking Note On Super Contrast Ila Assemblies 3.6 ILA Bias Settings3.7 CRT Mechanical Focus The lower-left rod adjusts the CRT to ILA distance z- axis 2. Increase Size to 100% horizontal and vertical 3.8 Electronic Focus Front/Rear Jumpers 3.9 Jumper SettingsF R O N T p ro jectio n R E A R p ro jectio nJ300 J301 J500 J501 Inverted Vertical JumpersJ200 J201 J600 J400 J601G2 Setting 3.10 G2 AdjustmentSensitivity/Threshold Offset To set G2 1. Cut off R and B and view G Model 330 Arc Lamp Alignment and Focus 3.11 Arc Lamp Alignment and FocusTo refocus the Model 330 Arc Lamp Y-Axis Plate Model 340SC and 370SC Arc Lamp Alignment and FocusX-Axis Plate Z-Axis Screwplate Figure 3-9. Model 340SC and 370SC Arc Lamp Adjustments 3.12 Arc Lamp Current Adjustment2. Measure the number of millivolts between pins 3 and 4 on SPS J505 Model 330, 340SC, 370SC Service Manual Chapter 3---Service Adjustments3-23 4.1 Introduction 4.0 Maintenance Remove/ReplaceContents Model 330, 340SC, and 370SC Service Manualbefore performing any removal and replacement procedures WARNING!!! Disconnect AC power from the projectorModel 330, 340SC, and 370SC Service Manual Chapter 4-MaintenanceFigure 4-1 Major components of the Model 330 Projector Model 330. 340SC, 370SC Service Manual Chapter 4-MaintenanceFigure 4-2 Major components of the Model 340SC and 370SC Projectors 4.3 Ventilation Filters 4.2 Projector CoversModel 330 Ignitor and Arc Lamp Assembly P/N 900611S Removal 4.4 Arc Lamp AssemblyJ503 and J504 Ignitor Assembly Wire goes to Wire ColorIgnitor Location onJ503 J504 J505 Interlock Switch Lamp Current Adjust Interlock Switch Fan Connector Circuit BreakerStart Capacitor Squirrel Cage Fan Cable 3-mm Set Screw Mounting Screws Collimating Condensing Lens Adjustment4.5 System Power Supply screws under lip AC Power Terminal Block Ground Main AC Circuit Breaker Mounting4.6 Electronics Module 11. Replace the module in the reverse order Model 330 CRT Removal 4.7 Cathode Ray Tube CRT5. Remove the video amplifier board from the CRT Assembly Section Figure 4-11 CRT Z-Axis Focus Adjustment Rods circled Figure 4-10 Model 340SC and 370SC CRT AssemblyChapter 4-Maintenance Model 330, 340SC, and 370SC Service ManualModel 340SC and 370SC CRT Removal 4.8 Video Amplifier Board VABTo remove a VAB see Figure 4-9 or Figure To remove the CRT yoke see Figure 4-9 or Figure 4.9 CRT Yoke4.10 High Voltage Power Supply HVPS 4.11 Card Cage Printed Circuit Boards 4.12 Image Light Amplifier Assembly Lens Locking Rods 4.13 Projection LensModel 330. 340SC, 370SC Service Manual Chapter 4-MaintenanceTable 4-2 for reference to part numbers, if necessary 4-24CAUTION! Never place the socket battery on a metal 4.14 SCB Socket Battery ReplacementLens Throw Lens Part Number or DesignationCAUTION! Never place the socket battery on Description 4.15 Recommended SparesQuantity 340SC5.1 General Information 5.0 TroubleshootingContents Page 5.2 Power-On Codes Code Second SetDescription Code 5.3 Break PointsMeaning DescriptionBreak Trap Data from the Diagnostics Menu Resetting the ProjectorCode DescriptionVersion 5.1.0 Software Menu Diagram 5.4 Main Menu StructureChapter 5---Troubleshooting Model 330, 340SC, and 370SC Service ManualPossible Solution Problem andService Symptom toPossible Solution Problem andService Symptom toPossible Solution Problem andService Symptom toPossible Solution Problem andService Symptom toPossible Solution Problem andService Symptom toPossible Solution Problem andService Symptom toIntermittent Glossary of Terms Cold Mirror Test pattern of black-to-white gradation bars. The more levels Intensity Lumen Resolution Phase adjustmentRaster RetraceScan See Arc Lamp temporarily with the Executive I/R remoteGlossary Model 330, 340SC, and 370SC Service Manual