JVC 250 User Manual

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SERVICE

MANUAL

Model 250 Projector

2310 Camino Vida Roble Carlsbad, California 92009

Phone: (760) 929-5300

Fax: (760) 929-5410

DECLARATION OF CONFORMITY

PER ISO/IEC GUIDE 22 AND EN 45014

Manufacturer

Hughes-JVC declares that this product conforms to the following Product Specifications (Directive/Standard):

Safety:EN 60950

EMC: EN 55022 (1988) / CISPR-22 (1986) Class "A"

In addition, the above product complies with the requirements of the Low Voltage Directive 73/23 EEC and the EMC Directive 89/336/EEC.

106784 First Edition May 1999

Hughes JVC 2310 Camino Vida Roble Carlsbad, Ca 92009 USA

IEC 950 (1992)

EN 50082-1 (1992) / IEC 801-2(1991) EN 50082-1 (1992) / IEC 801-3(1984) EN 50082-1 (1992) / IEC 801-4(1988)

ANSI C63.4-1992, FCC, Part 15, Class A

© Copyright 1999 by Hughes-JVC Technology Corporation. All worldwide rights reserved. This manual was produced by Hughes-JVC Technology Corporation and may be revised without prior notice. No part of this manual may be reproduced in any form without the express written permission of Hughes-JVC Technology Corporation. ILA® is a registered trademark of Hughes-JVC Technology Corporation.

Model 250 Service Manual

Table of Contents

Safety Information

....................................................................................v

Chapter 1 Introduction

1.1 Safety...................................................................................................... 1-1

1.2 Updates...................................................................................................1-2

1.3 Acronyms...............................................................................................1-2

Chapter 2 System Description

2.1 Introduction............................................................................................2-1

2.2 Electrical Section....................................................................................2-2

2.3 Optical Section.......................................................................................2-3

2.4 Electronic Section ..................................................................................2-5

2.5 Miscellaneous Items............................................................................... 2-7

Chapter 3 Electrical

3.1 Safety...................................................................................................... 3-1

3.2 Incoming Power Circuit.........................................................................3-2

3.3 Power Supplies....................................................................................... 3-3

3.4 Igniter Assembly....................................................................................-15

Chapter 4 Optical

4.1 Arc Lamp................................................................................................4-2

4.2 Optical Path............................................................................................ 4-7

4.3 ILA®.......................................................................................................4-12

4.4 Relay Lenses...........................................................................................4-19

4.5 Projection Lens....................................................................................... 4-19

Chapter 5 Electronic

5.1 Safety...................................................................................................... 5-1

5.2 Introduction............................................................................................5-2

5.3 System Controller PCB..........................................................................5-3

5.4 Video Processor PCB............................................................................. 5-11

5.5 Raster Timing Generator PCB ............................................................... 5-16

5.6 Horizontal Vertical Deflection PCB ......................................................5-21

5.7 Convergence Deflection PCB ................................................................ 5-28

5.8 Scan Reversal PCB.................................................................................5-34

5.9 Video Amplifier PCB............................................................................. 5-43

5.10 CRT/Yoke Assemblies.......................................................................... 5-51

5.11 VICs ...................................................................................................... 5-58

5.12 Backplane..............................................................................................5-74

Chapter 6 Miscellaneous Items

6.1 Projector Covers..................................................................................... 6-1

6.2 Electronics Module Tilt-up .................................................................... 6-2

6.3 Ventilation.............................................................................................. 6-3

6.4 Air Filters ............................................................................................... 6-4

Model 250 Projector Service Manual iii

6.5 IR Detectors............................................................................................6-4

6.6 EMI Shield ............................................................................................. 6-4

6.7 Cleaning Lenses, ILA® Assemblies, and Mirrors...................................6-5

Chapter 7 Troubleshooting

7.1 Safety...................................................................................................... 7-1

7.2 LEDs.......................................................................................................7-2

7.3 Diagrams ................................................................................................ 7-12

7.4 Error Codes ............................................................................................7-22

7.5 Troubleshooting Guide........................................................................... 7-25

Chapter 8 Software and Protocol

8.1 Software Updating..................................................................................8-1

8.2 Importing/Exporting............................................................................... 8-5

8.3 Terminals and Communication Protocol................................................8-10

Chapter 9 Parts

9.1 Replacement Parts List...........................................................................9-1

9.2 Recommended Spares............................................................................9-3

Glossary

.........................................................................................................A-1

Model 250 Service Manual

1.0 Introduction

Contents

1.1 Safety............................................................................................................ 1-1

1.2 Updates.........................................................................................................1-2

1.3 Acronyms Used............................................................................................1-2

The Model 250 Service Manual will provide information on how the each of the different components function individually and how they work together to take a source input image and project that image onto the screen. It will provide a list of the tools and procedures needed to perform necessary adjustments and to remove and replace components. The tools needed to perform any task are included in the procedure. The Model 250 Service Manual will provide diagrams and test points to help in diagnosing and troubleshooting. It will provide illustrations to show location and proper configuration of major and minor components. This manual will assist the Hughes-JVC Certified Technician with information to properly maintain and when necessary, troubleshoot the Model 250 projector. Use the Model 250 Service Manual in conjunction with the Model 250 User’s Guide.

Chapter 1---Introduction

The User’s Guide covers

! ! ! !

This Service Manual covers:

! ! ! !

Together, the Service Manual and User’s Guide provide a qualified service person with information to properly operate and maintain the projector.

1.1 Safety

This projector contains high voltages in the power supplies and around the CRTs and high intensity light sources in and around the Arc Lamp and optical path. Read the entire Safety Chapter at the front of this manual before performing any adjustments or maintenance.

Installation, Operation, Setup Adjustments Specifications

Projector functional description Service adjustments Removal and replacement of subassemblies Troubleshooting

Model 250 Service Manual 1-1

Chapter 1---Introduction

When performing procedures that call for the projector’s power to be on, always wear high voltage gloves (ANSI/ASTM 10,000 volt rated) when working around the CRTs, Arc Lamp or power supplies. Wear safety goggles (rated X5) when working near the light path from the Arc Lamp or at all times around the projection lens.

1.2 Updates

Hughes-JVC will periodically provide bulletins and /or manual supplements to ensure the continued accuracy of this service manual.

1.3 Acronyms Used

ALPS Arc Lamp Power Supply C Chrominance CDB Convergence/Deflection Board CH Channel CPU Central Processing Unit CRT Cathode Ray Tube EMI Electromagnetic Interference EPROM Erasable Programmable Read-Only Memory FPGA Field Programmable Gate Array F to V Frequency to Voltage G1 CRT Grid 1 G2 CRT Grid 2 HVDB Horizontal/Vertical Deflection Board Hz Hertz HSYNC Horizontal Sync HVDB Horizontal/Vertical Deflection Board HVPS High Voltage Power Supply IIC Inter-Integrated Circuit

ILA I/O Input/Output I/R I nfrared kHz Kilohertz LED Light Emitting Diode LVPS Low Voltage Power Supply NTSC National Television Standards Committee PAL Phase Alternating Line PCB Printed Circuit Board PLL P hase Lock Loop PLUGE Picture Line-Up Generating Equipment RAM Random Access Memory RGB Red, Green and Blue RGBHV Red, Green, Blue, Horizontal, Vertical ROM Read Only Memory RTG Raster Timing Generator SCB System Controller Board

Image Light Amplifier

1-2 Model 250 Service Manual

Chapter 1---Introduction

SECAM Sequential couleur a memoire (sequencial

color with memory SRB Scan Reversal Board SYNC Synchronization TTL Transistor-Transistor Logic UL Underwriter Laboratories UV Ultraviolet VAB Video Amplifier Board VCO Voltage Controlled Oscillator VIC Video Input Card VIN Video Input VPB Video Processor Board VSYNC Vertical Sync VTR Video Tape Recorder Y Luminance

Model 250 Service Manual 1-3

2.0 System Description

Contents

2.1 Introduction.................................................................................................. 2-1

2.2 Electrical Section..........................................................................................2-2

Incoming Power Circuit............................................................................. 2-2

Power Supplies........................................................................................... 2-2

Igniter Assembly........................................................................................ 2-3

2.3 Optical Section............................................................................................. 2-3

Arc Lamp Module...................................................................................... 2-3

Optical Path................................................................................................ 2-3

ILA®s..........................................................................................................2-4

CRTs .......................................................................................................... 2-4

Relay Lenses ..............................................................................................2-5

Projection Lens...........................................................................................2-5

2.4 Electronic Section ........................................................................................2-5

VICs ........................................................................................................... 2-5

PCBs........................................................................................................... 2-6

CRT/Yoke Assemblies............................................................................... 2-7

2.5 Miscellaneous Items..................................................................................... 2-7

Projector Covers......................................................................................... 2-7

IR Detectors................................................................................................2-7

Cooling Fans .............................................................................................. 2-7

Air Filters ................................................................................................... 2-7

EMI Shield................................................................................................. 2-8

Chapter 2---System Description

2.1

Model 250 Service Manual 2-1

Introduction

This chapter is divided into four basic sections: the Electrical Section, the Optical Section, the Electronic Section and the Miscellaneous Items. Each section gives a basic description of the components in the section and a description of the function of those components. This provides an overall view of the projector and its subsystems for a general understanding of how these systems contribute to the function of the projector.

Chapter 2---System Description

Figure 2-1

2.2

Overview of the Model 250 projector showing major components

Electrical Section

The electrical section consists of the Incoming Power Circuit, and the Power Supplies and the Igniter Assembly. The following paragraphs give a list of major components and a brief description of those components. For a more detailed description of a component, refer to the chapter and section dedicated to that particular component.

Incoming Power Circuit

Power Cord - The AC power comes in through the Power Cord to the AC Circuit Breaker.

AC Circuit Breaker - The Circuit Breaker connects and disconnects the projector from electrical energy and protects the projector from overvoltage conditions.

AC Line Filter - The AC SF Series Line Filter reduces radiation generated by a regulated power supply from returning to the AC power source.

Power Supplies

Low Voltage Power Supply (LVPS) - The LVPS supplies standby voltages and the main system voltages to the projector.

Arc Lamp Power Supply (ALPS) - The ALPS supplies power to the Igniter Assembly while the Arc Lamp is lighting. After the Arc Lamp has lit, ALPS provides the steady state power to the Arc Lamp. The ALPS also monitors the condition of the Arc Lamp and sends a feedback signal to the System Controller PCB if there is a problem.

High Voltage Power Supply (HVPS) - The HVPS provides the Anode, Focus (G3), Black Level (G2), Blanking (G1), and Dynamic Focus voltages for the CRT.

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Chapter 2---System Description

Igniter Assembly

The Igniter Assembly provides the high voltage pulse that lights the Arc Lamp and acts as a link from the Arc Lamp Power Supply to the Arc Lamp after the Arc Lamp has been lit.

Igniter - The Igniter actually performs three functions. It is a step-up transformer that supplies the high voltage pulse to light the Arc Lamp. It also supplies the spark gap for the high voltage pulse. Once the Arc Lamp is lit, the Igniter acts as a link between the Arc Lamp Power Supply and the Arc Lamp for steady state operation.

Laser Power Supply - The Laser Power Supply provides the voltage for the spark gap. The spark gap produces a high voltage pulse in the Igniter that lights the Arc Lamp.

2.3

Optical Section

The optical section of the Model 250 consists of the Arc Lamp Module, the Optical Path, the ILA®, the CRTs, the Relay Lenses and the Projection Lens.

Arc Lamp Module

The Arc Lamp Module supplies high intensity light for the Model 250. Its output is rated at 2 kW. The Arc Lamp has an expected 50% lifetime (half of initial light output) of 1000 hours.

Optical Path

The Optical Path consists of all the optical components that transmit, filter, separate, bend, or straighten the Arc Lamp light. The Optical Path also includes Polarizing Prisms, Prepolarizing Prisms, Steering Prisms and the 4P Combining Prism that control the image path inside the Prism Assembly.

Cold Mirrors (3) - The Cold Mirrors remove infrared light rays, which contain most of the heat, from the white light coming from the Arc Lamp. There are three Cold Mirrors, the first one is located in front of the Arc Lamp, and the other two are located after the Light Pipe.

CAUTION!

The term "cold mirror" is used because the mirror passes infrared light and its reflection contains only "cold' light that does not transmit appreciable heat. As a result of the absorption of infrared heat radiation, "

Light Pipe - The Light Pipe acts as an Integrator to spread out the beam of

cold" mirrors get very hot

light creating a uniform distribution of light across the face of the ILA®. This will result in a more uniform image on the screen

Model 250 Service Manual 2-3

Chapter 2---System Description

Condensing Lenses (2) - The Primary Condensing Lens collects all the light from the Light Pipe and begins to bend the light rays into a straight path. The Secondary Condensing Lens works with the Primary Condensing Lens to collimate or “straighten” the light path before it enters the Dichroic Beamsplitter Assembly.

UV Filter - The UV Filter removes much of the unwanted ultravioltet light from the white light of the Arc Lamp.

Dichroic Beamsplitter Assembly w/ Steering Mirrors - The Dichroic Mirrors separate white light into Red, Green, and Blue component colors. The Steering Mirrors direct the separated light beams into the Prism Assembly.

Prism Assembly - The Prism Assembly is a large tank filled with optical fluid. It houses the following optical components:

Pre-polarizing Beamsplitter - The Pre-polarizing Beamsplitter

performs the first part of the polarizing process. Polarizing Beamsplitter - The Polarizing Beamsplitter performs the

final function of the polarizing process. Steering Prisms - When the polarized light leaves the Prism

Assembly and enters the ILA®, the light is modulated by the ILA®. The modulated light reflects off the ILA® mirror and returns to the Prism Assembly. Inside the Prism Assembly, the light for the red and blue reflect off the two Steering Mirrors (one for red, one for blue) and enter the 4P Combining Optic.

4P Combining Optic - The 4P Combining Optic takes the three

colored image lights from the ILA®s and combines them so they leave the Prism Assembly as a single beam of image light. That image light continues on to the Projection Lens

ILA®s - Image Light Amplifier (3)

The ILA® is a very important component in the Hughes-JVC projectors. The ILA® modulates the polarized light from the Arc Lamp. The image light from the

CRT that strikes the input side of the ILA

interacts with the Liquid Crystal layer of the ILA® to impose an image on the polarized light from the Arc Lamp. The Model 250 Projector uses the Super Contrast ILA®. The Super Contrast ILA® has a sequential contrast ratio of 600:1 @ center screen.

CRTs (3)

There are three Cathode Ray Tubes (CRTs), one for each color. The CRT generates the image light that strikes the input of the ILA®. CRTs are covered in the Electronics Section.

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Chapter 2---System Description

Relay Lens Assemblies (3)

There are three Relay Lenses, one for each color. The Relay Lens focuses the image light from the CRT onto the photosensitive layer on the input side of the ILA®. The Relay Lens is physically connected to the CRT (see Figure 2-2).

Front Projection Lens

The Model 250 comes with a choice of four standard lenses. These include a motorized Zoom Lens or one of three Fixed Lenses. All Projection Lenses have motorized focus.

Motorized Zoom 2:1-4:1

Fixed Lens

0.96

1.5:1

5.6:1

2.4

Electronic Section

The electronics section consists of the Input Cards (VICs), the Printed Circuit Boards (PCBs), and the CRT/Yoke assemblies.

Input Cards (VICs)

There are two standard Input Cards and four optional VICs. The Input Cards are the first stop for the source input signal. They provide the RGB and Sync interface for the projector. All VICs are IIC controlled.

Standard VICs:

Standard RGBHV VIC - The RGBHV VIC is a straight feed-through with an IIC selection control.

Graphic Enhancer Plus VIC - The Graphics Enhancer Plus VIC is exactly the same as the RGBHV VIC except for a Menu controlled adjustment for black on white graphics and text display

Optional VICs:

YPbPr VIC - Composite Video Decoding for YPbPr

Quad Standard Decoder VIC - Composite Video Decoding (NTSC, SECAM, and PAL)

Quad Standard Decoder and Line Doubler VIC - Composite Video Decoding (NTSC, SECAM, and PAL) with Line Doubling

Four-Input RGBHV - Four- Input RGBHV with IIC controlled Mux (switcher)

Model 250 Service Manual 2-5

Chapter 2---System Description

Printed Circuit Boards (PCB)

The Model 250 Projector has eight main PCBs:

System Controller PCB - System Controller PCB controls much of the electronics system. It uses digital and analog circuitry to generate Menu and internal pattern overlays, and directs convergence correction and shading information. It controls the IIC data bus that sends geometric correction and VIC selection data. The System Controller PCB controls and monitors the status of power supply operations during and after the projector is powered ON.

Raster Timing Generator PCB - The Raster Timing Generator PCB generates an internal sync for the PLL (Phase Lock Loop) circuitry. It provides sync detection and selection. It also generates the blanking pulse, provides horizontal and vertical phase adjustments, and Interlace detection.

Video Processor PCB - The Video Processor PCB receives external image and sync signals and sends horizontal sync, vertical sync, and green sync signals to the Raster Timing Generator PCB. It adds Contrast, Brightness, Sensitivity and Threshold adjustments to the image signals and sends the image signals, G2 control lines, and G1 bias to the Video Amplifier PCB.

Horizontal Vertical Deflection PCB - The Horizontal Vertical Deflection PCB supplies the deflection waveforms that drive the deflection yokes on the CRTs for the horizontal and vertical raster. It integrates the geometry correction such as pincushion, keystone, and vertical linearity onto the horizontal deflection waveform and adjusts the horizontal and vertical center raster.

Convergence Deflection PCB - The Convergence Deflection PCB generates the horizontal and vertical convergence correction waveforms. It generates the horizontal and vertical Dynamic Focus Parabola used by the High Voltage Power Supply. The Convergence Deflection PCB also

provides the ILA

Scan Reversal PCB - the Scan Reversal PCB reverses the deflection

bias and sensitivity.

waveforms for both the horizontal and vertical axes for floor/ceiling mounting and front/rear mounting. It also provides scan failure detection to protect the CRT.

Video Amplifier PCB - The Video Amplifier PCB amplifies the video signals and drives the cathodes for all three CRTs. It senses the cathode beam current and regulates the G

and G2 for all the CRTs. The Video

Amplifier PCB also provides phosphor protection for all three CRTs and CRT interface for the Focus, Heater Voltage, and Arc ground.

Backplane - The Backplane sits in the back of the Electronics Module. The System Controller PCB, Raster Timing Generator PCB, Video Processor PCB and the VICs plug into directly the Backplane PCB. It

2-6 Model 250 Service Manual

Chapter 2---System Description

provides an interconnection interface for all the electronic components in the projector.

CRT/Yoke Assemblies

The CRT/Yoke Assemblies bridge between the Optical and the Electronic sections. The CRTs could be included in the Optical section because they produces the image light transmitted to the ILA®s, but they are included in the Electronic section because they are the end user for the image signals from the VICs, Video Processor PCB, and Video Amplifier PCB. The CRTs also use the Anode, Focus, G1, and G2 voltages from the High Voltage Power Supply. The Yoke Assemblies contains the deflection and convergence coils. The deflection coils are the end-user for the horizontal and vertical deflection waveforms from the Horizontal Vertical Deflection PCB. The convergence coils use the convergence data from the Convergence Deflection PCB.

2.5

Miscellaneous Items

The Miscellaneous Items section consists of components that indirectly support the main function of the projector.

Projector Covers

All Series 200 projectors including the Model 250 have a front and rear cover. Both covers can be tilted up and/or removed to service the projector. The covers should not be opened while the projector is operating without proper safety protection (review the Safety Chapter).

IR Detectors

The Model 250 can be controlled by a handheld IR Remote Control. The IR (Infrared) Detectors receive infrared pulses from these remote controls and use them to control various functions of the projector. One IR Detector is mounted on the front of the projector, the other is mounted on the System Controller PCB at the rear of the projector. IR Detectors can receive commands from the remote control from a range of about 45-ft. line of sight.

Cooling Fans

The Model 250 has eleven cooling fans of various sizes plus a large blower for the Arc Lamp. The cooling fans maintain thermal stability for the projector. The Arc Lamp especially depends on the cooling fans. If the fans are not operating while the Arc Lamp is on, the Lamp will implode from overheating. Many of the Printed Circuit Boards generate a lot of heat and require airflow from the cooling fans. The fans provide cooling to the PCBs and CRTs to maintain for stable operation.

Air Filters

The Model 250 has three air filters (see Figure 2-2). The Air Filters filter the incoming air to minimize the amount of dust and air-borne particles inside the

Model 250 Service Manual 2-7

Chapter 2---System Description

projector. These air-borne particles can land on optics such as the ILA® and cause large diffuse dark areas on the screen.

EMI Shield

The Model 250 has an EMI (Electro-Magnetic Interference) Shield that traps and collects high frequency noise that is radiated by switching power supplies such as the Arc Lamp Power Supply and the Low Voltage Power Supply. This high frequency noise can interfere with the operation of radios, televisions, and other electronic devices.

Figure 2-2

2-8 Model 250 Service Manual

Relative location of CRTs, Relay Lenses, ILA®s, and Air Filters.

Chapter 2---System Description

Model 250 Service Manual 2-9

3.0 Electrical

Contents

3.1 Safety............................................................................................................ 3-1

3.2 Incoming Power Circuit............................................................................... 3-2

AC Power Cord.......................................................................................... 3-2

AC Circuit Breaker.....................................................................................3-2

AC EMI Filter ............................................................................................ 3-2

3.3 Power Supplies............................................................................................. 3-3

Low Voltage Power Supply ....................................................................... 3-3

Arc Lamp Power Supply............................................................................3-5

High Voltage Power Supply....................................................................... 3-9

3.4 Igniter Assembly.......................................................................................... 3-15

Chapter 3---Electrical

3.1 Safety

review the chapter on Safety at the beginning of this manual.

that require projector covers to be off,

(ANSI/ASTM 10,000 volt rated) when working near the CRTs, Arc Lamp, or power supplies. Wear safety goggles (rated X5) when working anywhere near the light path from the arc lamp or the projection lens

data be downloaded ( performing any of the following procedures. Exporting baseline source setup data to disk is an excellent precautionary measure. It will save the

time of setting up new source file(s) in the case of an unexpected problem

CAUTION

WARNING

CAUTION

Exported, see section 8.2 Importing/Exporting

Before performing procedures in this chapter,

When performing procedures in this chapter

!!!

wear high voltage gloves

It is very strongly recommended that setup

) before

Model 250 Service Manual 3-1

Chapter 3---Electrical

3.2.

Left/Right Orientation:

reference to standing at the rear of the projector, facing the screen.

Connectors

before pulling on the connector. The proper procedure is to push slightly IN on the connector, then squeeze the tab, then pull the connector out.

on subassemblies and PCBs have tabs that must be released first

When referring to the left or right in this c hapter, it is with

Incoming Power Circuit

AC Power Cord

The Power Cord performs one basic function: to deliver the AC power from the power source to the projector. It must be configured to meet the Electrical Specifications for the region the projector will be used. The Power Cord type is NEMA 5-20, 20A, 250A.

AC Circuit Breaker

The AC Circuit Breaker has two basic functions: one is to connect and disconnect electrical power from the projector, the second is to protect the projector from over-voltage conditions.

When the AC Circuit Breaker is in the OFF position, no electrical energy will reach any part of the projector except for the AC Circuit Breaker. When the AC Circuit Breaker is in the ON position, electrical energy goes to the AC Line Filter and on to the Low Voltage Power Supply and Arc Lamp Power Supply. When the AC Circuit Breaker is in the ON position but the projector has not received the POWER ON command either from an IR Remote Control or from a PC or Laptop computer, the projector is in Standby mode. In the Standby mode, the +5.1 V Standby and the +24 V Standby Voltages maintain power to the CPU chips on the System Controller PCB, the IR Detectors, and to the cooling fans.

The AC Circuit Breaker is rated at 90-264 Vac (RMS), 50/60 Hz. The current rating is 13 Amps RMS at 90 Vac.

The power requirements of the Model 250 Projector are 200-264 Vac, 50/60 Hz, single phase. The power consumption is rated at 2800-Watts maximum.

AC EMI Filter

The AC EMI (Electro-Magnetic Interference) Filter prevents switching noise from a regulated power supply such as the Low Voltage Power Supply and the Arc Lamp Power Supply, from returning to the AC power source. This switching noise interferes with the operation of radios, televisions, and other electronic appliances

3-2

Model 250 Service Manual

3.3 Power Supplies

All Series 200 projectors including the Model 250 have three power supplies. These include:

Low Voltage Power Supply

Arc Lamp Power Supply

High Voltage Power Supply

There is a fourth power supply, the Laser Power Supply, but that power supply is used only for the Igniter Assembly during Arc Lamp lighting.

Low Voltage Power Supply (LVPS)

LVPS - Main Functions:

Provides all the low voltages needed by the projector.

Provides standby power (+5.1V) when the projector is OFF but the AC Circuit Breaker is in the ON position.

Chapter 3---Electrical

Provides power (+24 V) for all cooling fans.

LVPS - Inputs

The Low Voltage Power Supply receives AC input power directly from the AC Line Filter. The input range is from 220 VAC to 240 VAC, at 50/60 Hz.

/LV_ENA - from the System Controller PCB. This signal enables the LVPS when the System Controller receives a Power On command.

/FAN_ENA - from the System Controller PCB. This signal enables the +24v standby voltage for the projector fans.

/COVER_ON - signal enables the non-standby outputs. / = Active low

LVPS - Outputs:

+ 5.1VDC Main

+ 5.1VDC Stdby

+ 6.2VDC

± 15VDC

+ 24VDC

+ 80VDC

/LV_OK - this diagnostic signal tells the System Controller PCB the status of the non-standby supply (all the outputs are working or not working).

Model 250 Service Manual 3-3

Chapter 3---Electrical

Figure 3-1

Low Voltage Power Supply I/O Diagram.

LVPS - Operation:

AC power is delivered to the Low Voltage Power Supply from the AC line filter. The AC is rectified to a DC Voltage, filtered, and goes through a power factor correction circuit to force the current waveform to follow the voltage waveform.

The +5.1V Standby is on whenever AC power is connected to the projector and the circuit breaker on the rear panel is in the ON position. When the AC Circuit Breaker is in the ON position, the LVPS supplies the +5.1 V to the System Controller PCB. The System Controller PCB drives the /FAN_ENA signal to the LVPS to turn on the +24V Standby power for the cooling fans. If the System Controller PCB does not receive a POWER ON command from an IR remote control or a PC, it waits about 10 minutes and then tells the LVPS (/FAN_ENA goes high) to shut off +24V Standby power. This shuts off the cooling fans. More importantly, after the System Controller PCB receives a POWER OFF command it waits 10 minutes, and then tells the LVPS to shut off the cooling fans. This gives the Arc Lamp and the PCBs time to cool down to avoid damage or reduction of operating life.

When the projector receives a POWER ON command from an IR Remote Control or PC, the System Controller PCB sends the /LV_ENA signal to the LVPS. The Low Voltage Power Supply needs to receive the /LV_ENA from the System Controller PCB and the /COVER_ON signal to activate all the non-standby voltages. These include:

3-4

Model 250 Service Manual

Chapter 3---Electrical

+5.1V for digital components

+6.2V for CRT filaments

±15V for analog circuits

+80V supply used by the High Voltage Power Supply, Video Amplifier PCB, and the Horizontal/Vertical Deflection PCB.

LVPS - Service Adjustments

There are no service adjustments for the Low Voltage Power Supply.

LVPS - Remove and Replace

Tools Needed:

#2 Posi-drive Phillips-head screwdriver

Parts Needed:

Low Voltage Power Supply - p/n 102520

To remove the Low Voltage Power Supply:

Power off the projector by IR Remote or PC, and allow the cooling fans to run until they shut off.

Turn the AC Circuit Breaker to the OFF position and unplug the AC Power Cord.

Remove the front cover (see Projector Covers section 6.1).

Remove the lower-right-side panel by removing the 5 Pozi-drive screws securing it.

Remove the 5 Pozi-drive screws securing the EMI Shield. Slide the shield to the left and remove it.

Remove J76 (DC Output) and J75 (AC Input) from the left side of the Low Voltage Power Supply.

NOTE

: These connectors may be a little difficult to remove and it may be

necessary to pull the LVPS partly out of the chassis in order to get a better grip on the connectors.

Carefully slide the Low Voltage Power Supply out of the projector.

Reinstall the LVPS in reverse order. After installing a new LVPS, it may be necessary to touch-up the Timing, Geometry, Electronic Focus, ILA Bias/Sensitivity, Convergence, G2, and Shading.

Arc Lamp Power Supply (ALPS)

ALPS - Main Functions:

Provides ignition power to turn the Arc Lamp ON (via the Igniter).

Provides steady state power to maintain the Arc Lamp operation.

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Chapter 3---Electrical

ALPS - Inputs: AC input power: Directly from the AC Line Filter. The input range is from 220-

240 VAC, at 50/60 Hz. /LAMP_ENA - from the System Controller PCB. Turns on the ALPS. /COVER_ON - signal enabling the Arc Lamp Power Supply. /LAMP_OK - the input is jumpered at the Arc Lamp Power Supply (tied to

ground) so it is always low. / = Active Low

ALPS - Outputs:

+170 VDC output during the boost phase to get Arc Lamp ignition. This supplies the power for the Igniter.

Run Voltage - 25 to 31 V to maintain the arc lamp operation.

Current - 70 to 85 amps to maintain the arc lamp operation.

LAMP_OUT - Lamp output voltage, positive.

LAMP_RTN - Lamp return.

/LAMP_LIT - signal to System Controller PCB indicating that the Arc Lamp is lit.

/LAMP_OK - signal to System Controller PCB (no real indication).

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Model 250 Service Manual

Chapter 3---Electrical

Figure 3-2

Arc Lamp Power Supply signals and voltages.

ALPS - Operation:

Three signals (/LAMP_ENA, /COVER_ON, and /LAMP_OK) are required in order for the Arc Lamp Power Supply to light the Arc Lamp. The /LAMP_OK (active low) input is jumpered to ground at the Arc Lamp Power Supply, so it is always low. The Arc Lamp Power Supply sends the /LAMP_OK to the System Controller PCB. The System Controller PCB then sends the /LAMP_ENA signal back to the Arc Lamp Power Supply and activates the Arc Lamp Power Supply.

Once the Arc Lamp Power Supply receives the /LAMP_ENA signal from the System Controller PCB, it supplies the +170 VDC boost voltage to the primary coil of the Igniter. The Laser Power Supply charges up a capacitor. When the capacitor reaches +5.5 kV, a spark gap arcs causing a very high voltage pulse (approximately 32 kV) to be induced onto the secondary coil inside the Igniter. This high voltage pulse ignites the Xenon Arc Lamp. Immediately after the Arc Lamp lights, the voltage from the Arc Lamp Power Supply drops to about 25-31 volts at 70-85 amps. It will stay at this level during normal Arc Lamp operation.

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Chapter 3---Electrical

The Arc Lamp Power Supply sends the /LAMP_LIT signal back to the System Controller when the Arc Lamp is lit.

The Arc Lamp regulates its output to give a constant Arc Lamp power. If the Arc Lamp has not lit within 20 seconds (/LAMP_LIT still high), the System Controller PCB will try once more to re-initiate the sequence. If the Arc Lamp still fails to light, an error code will appear on the back panel (see section 7.22 Error Codes).

The Arc Lamp Power Supply negative output goes to the Cathode of the Arc Lamp. The positive output goes to the Anode of the Arc Lamp and is tied to chassis ground.

The Arc Lamp Power Supply is shielded electrically and magnetically to prevent noise or disturbances in the CRTs or other circuitry.

3-8

Figure 3-3

Arc Lamp Power Supply connections.

ALPS - Service Adjustments

The Arc Lamp Power Supply for the Model 250 is preset at the factory and does not have any Service Adjustments. The output is programmed for a constant 2 kW. Arc Lamp replacement does not require any electrical readjustments.

ALPS - Remove and Replace

Tools Needed

#2 Pozi-drive Phillips-head screwdriver

Parts Needed

Arc Lamp Power Supply p/n - 105216

To remove the Arc Lamp Power Supply (ALPS):

Power off the projector by IR Remote or PC, and allow the cooling fans to run until they shut off.

Model 250 Service Manual

Chapter 3---Electrical

Turn the AC Circuit Breaker to the OFF position and unplug the AC Power Cord.

Remove the front cover (see section 6.1 Projector Covers ).

Remove the lower-right-side panel by removing the five Pozi-drive screws securing it.

Remove the five Pozi-drive screws securing the EMI Shield. Slide the shield to the left and remove it.

Disconnect the INPUT AC plug.

Disconnect the two CONTROL SIGNALS cables. The /LAMP_OK signal jumper is attached to the CONTROL SIGNAL cable by a cable tie. Do not cut this cable tie.

Disconnect the Arc Lamp Power Supply OUTPUT cables from the (+) and (-) terminals. Take care not to damage the 470µf capacitor across the output cables. The (+) cable has a red shrink tubing on it; the (-) has a black shrink tubing on it.

NOTE

: The capacitor on the output of the Arc Lamp Power Supply filters

transient spikes from the Arc Lamp when it arcs. Re-attach the capacitor with the Arc Lamp output leads during reinstallation of new Arc Lamp Power Supply.

Remove the 1 Pozi-drive Phillips-head screws from the bottom of the front of the Arc Lamp Power Supply. The other screw was removed with the EMI Shield.

10.

Carefully slide the Arc Lamp Power Supply out of the projector.

11.

Replace the Arc Lamp Power Supply in the reverse order.

High Voltage Power Supply (HVPS)

HVPS - Main Functions

The High Voltage Power Supply provides the following functions:

Phase locked loop circuit for synchronization of the High Voltage Power Supply to the HVPS_SYNC

Generation of Anode voltages (25 kV) for all three CRTs (RGB)

Generation of Focus voltage (G3) (7 kV) for all three CRTs (RGB)

Generation of G2 (1200 V) supply voltage for the Video Amplifier PCB.

Generation of G1 (-150 V) supply voltage for the Video Amplifier PCB.

Dynamic Focus Amplifier using horizontal and vertical parabolas supplied to the High Voltage Power Supply.

External CRT Protection and generation of /HV_OK signal

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Chapter 3---Electrical

Figure 3-4

High Voltage Power Supply I/O signals.

HVPS - Inputs

HVPS_SYNC - this signal is generated on the Raster Timing Generator PCB. Square wave HCT level with 50 or 33% duty cycle. The signal is synchronized to horizontal sync.

/HV_ENA - The HVPS shutdown signal from the Video Amplifier PCB (/VA_OK).

H_PARABOLA - The horizontal parabola from the Convergence Deflection PCB used by the Dynamic Focus Amplifier.

V_PARABOLA - The vertical parabola from the Convergence Deflection PCB used by the Dynamic Focus Amplifier.

± 15 V. - The power source for the analog circuitry in the High Voltage Power Supply.

+ 80 V. - The input power for the High Voltage section of the High Voltage Power Supply.

HVPS - Outputs

G1 Supply - goes to Video Amplifier PCB

3-10

G2 Supply - goes to Video Amplifier PCB /HV_OK - goes to System Controller PCB

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Chapter 3---Electrical

RGB Anode Voltage - goes directly to each CRT RGB Focus Voltage - goes directly to each CRT Arc Ground - The Arc Ground protection for each CRT from the Video Amplifier

PCB.

HVPS - Operation

The High Voltage Power Supply has three basic functions.

High Voltage Generation

Focus Voltages

High Voltage and CRT Protection

High Voltage Generation - The High Voltage Amplifier section converts the +80 V from the Low Voltage Power Supply, to 25 kV, and divides it into three outputs for each CRT. It also uses the HVPS_SYNC signal from the Raster Timing Generator PCB. This signal is synchronized to the horizontal sync to eliminate one source of moving noise on the screen. The High Voltage section also supplies the G2 Voltage for the Video Amplifier PCB.

Focus Voltages - The High Voltage Power Supply receives the horizontal and vertical parabolas from the Convergence Deflection PCB and adds them together. They are amplified and sent to the Focus Pack section. The Focus Pack section couples the amplified parabola waveforms to the Focus Voltages. The Focus Pack divides the Focus Voltage into three signals and outputs each signal to a CRT. The DC Focus Voltages are manually adjusted as necessary.

The Arc Ground signal goes to the Video Amplifier PCB and from there, connects to the CRT. It provides a direct return path for arc currents in the event of internal CRT arcing.

High Voltage and CRT Protection - The High Voltage Power Supply receives a /HV_ENA (/VA_OK) signal from the Video Amplifier PCB. This signal goes to the Protect OR section. The Protect OR section also checks the incoming +80 V. from the LVPS for an overcurrent condition. The Protect OR section also monitors the high voltage output for an overvoltage condition. If any of these checks shows a problem the Protect OR section shuts down the high voltage amplifier. The Protect OR section outputs the /HV_OK signal telling the System Controller PCB that the High Voltage Power Supply is functioning properly.

HVPS - Service Adjustments

Normally, the only High Voltage Power Supply adjustments are for CRT Focus. The CRT Focus Voltage adjusts are mechanical potentiometers located on the side of the High Voltage Power Supply (see Figure 3-5) that adjust the focus for each CRT. The CRT Focus Voltage adjustments are detailed in the CRT Section (see section 5.10 CRT/Yoke Assemblies).

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Chapter 3---Electrical

HVPS - Remove and Replace

Tools Needed

#1 Pozi-drive Phillips-head screwdriver #2 Pozi-drive Phillips-head screwdriver small Flathead screwdriver

Parts Needed

High Voltage Power Supply p/n 102566

To remove the High Voltage Power Supply:

Power off the projector by IR Remote or PC, and allow the cooling fans to run until they shut off.

Turn the AC Circuit Breaker to the OFF position and unplug the AC Power Cord.

Remove the front cover.

Remove the High Voltage Power Supply cover (see Figure 3-5) by removing the 1 Pozi-drive screw that secures the HVPS at the bottom of the cover and loosening the 2 Pozi-drive screws at the top of the front flap.

Figure 3-5

Electronic

Focus

Adjustment

High Voltage Power Supply cover.

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Chapter 3---Electrical

Table 3-1

HVPS - P45 I/O Pinout

PIN # Description PIN # Description

1 GND (+80V) 9 +15V 2 GND (+15V) 10 -15V 3 GND (-15V) 11 G1 SUPPLY 4 GND (G1) 12 /HV_ENA 5 /HV_OK 13 V PARABOLA 6 H PARABOLA 14 H DRIVE (HVPS_SYNC 7 GND (DAF) 8 +80V

Figure 3-6

Carefully slide the cover upward and outward to remove it.

NOTE

Disconnect the three CRT Anode Cables.

Disconnect P44-G2 Out (at the middle-front of the HVPS).

Unsnap the cable clamp at the top of the HVPS.

Remove the Anode Cables and the P44 cable from the cable clamp.

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: Refer to Figure 4-5 for the remainder of this procedure.

High Voltage Power Supply.

Chapter 3---Electrical

10.

Disconnect P45 (“Control”) at upper left of HVPS.

11.

Disconnect and label the three Focus cables. The square tabs on these cables (see Figure 3-6) may have to be lifted up. Gently pry up with a small Flathead screwdriver.

12.

Remove all the cables from the slot in the cable guide located on the left side of the HVPS.

13.

Verify that all plugs and cables are removed and out of the way so the HVPS is free to be removed.

14.

Loosen (do not remove) the two Posi-drive screws (at the bottom of the HVPS) that secure the HVPS metal housing to the projector.

15.

Remove the two Posi-drive screws that hold the top of the HVPS metal housing to the projector frame.

16.

Grasp the HVPS at the bottom and lift upward and outward so that it slides away from the bottom screws.

17.

Reinstall the High Voltage Power Supply in the reverse order.

NOTE

: When reinstalling the High Voltage Power Supply:

Make sure it slides over the bottom screws and the lip at the top of the projector frame.

Make sure each anode cable “snaps” back into its receptacle. The receptacles are about 2” inside the hole where the cable goes.

Make sure the rear flap on each focus cable connector snaps over the square socket securely. Wiggle the connector a little to make it fits securely.

18.

Replace the HVPS cover.

19.

Replace the projector covers.

20.

After replacing the HVPS, check and adjust Electronic Focus as necessary.

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Model 250 Service Manual

3.4 Igniter Assembly

The Igniter Assembly consists of the Igniter and the Laser Power Supply. The Igniter and Laser Power Supply are replaced as one unit.

Igniter Assemby - Main Functions:

Generates 32 kV pulse to light Arc Lamp Power

Acts as link between Arc Lamp Power Supply and Arc Lamp during normal Arc Lamp operation

Igniter Assembly - Inputs

+170 V - From the Arc Lamp Power Supply during Arc Lamp lighting.

25-31 V at 70-85 A - From Arc Lamp Power Supply during normal Arc Lamp operation.

Igniter Assembly - Outputs

32 kV - to the Arc Lamp during Arc Lamp lighting.

25-31 V at 70-85 A - From Arc Lamp Power Supply during normal Arc Lamp operation.

Chapter 3---Electrical

Igniter Assembly - Operation

The Igniter has two functions: to light the Arc Lamp and to act as a link between the Arc Lamp Power Supply and the Arc Lamp during normal Arc Lamp operation. The Igniter contains the spark gap and the step-up transformer that supplies the 32 kV pulse that lights the Arc Lamp. During lighting of the Arc Lamp, the Arc Lamp Power Supply receives the /LAMP_ENA signal from the System Controller PCB, it sends a +170 VDC boost voltage to the primary coil of the Igniter. The Laser Power Supply charges up a capacitor. When the capacitor reaches +5.5 kV, the spark gap arcs causing a very high voltage pulse (approximately 32 kV) to be induced onto the Igniter Transformer step-up (secondary) coil. The high voltage pulse goes to the Anode of the Arc Lamp. The spark generated by the 32 kV pulse creates an arc inside the Xenon bulb that ignites the Arc Lamp.

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Chapter 3---Electrical

Figure 3-7

Igniter Assembly.

Igniter Assembly - Service Adjustments

There are no service adjustments performed on the Igniter Assembly.

Igniter Assembly - Remove and Replace

Replace the Igniter and the Laser Power Supply as one unit. Tools Needed 2 - 7/16-inch wrench (one open end wrench) #1 Pozi-drive Phillips-head screwdriver Parts Needed Igniter Assembly p/n 106570 To remove the Igniter Assembly

1. Power the projector Off by IR Remote or PC, and allow the cooling fans

to run until they shut off.

2. Turn the AC Circuit Breaker to the OFF position and unplug the AC

Power Cord.

3-16

3. Remove the front cover (see Projector Covers section 6.1).

4. Disconnect the white Anode cable from the output of the Igniter

Transformer using the 7/16-inch wrench. Use one wrench to hold the inside nut and the other wrench to loosen the outside nut.

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Chapter 3---Electrical

5. Disconnect the orange cable attached to the input side of the Igniter

Transformer using the 7/16-inch wrench. This cable will have black shrink sleeving on it. It goes to the negative terminal of the Arc Lamp Power Supply.

6. Disconnect the orange Cathode cable from the Igniter ground post using

the 7/16-inch wrench. Remove the other orange cable that goes to the positive terminal of the Arc Lamp Power Supply.

7. Remove the five #1 Pozi-drive Phillips-head screws.

8. Lift the Igniter Assembly out of projector.

9. Reverse the procedure to install the Igniter Assembly.

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4.0 Optical

Contents

4.1 Arc Lamp......................................................................................................4-2

4.2 Optical Path.................................................................................................. 4-7

4.3 ILA®.............................................................................................................4-13

4.4 Relay Lenses ................................................................................................ 4-20

4.5 Projection Lens............................................................................................. 4-20

Chapter 4---Optical

CAUTION!

review the chapter on Safety at the beginning of this manual.

WARNING!!!

that require projector covers to be off, wear high voltage gloves (ANSI/ASTM 10,000 volt rated) when working near the CRTs, Arc Lamp, or power supplies. Wear safety goggles (rated X5) when working anywhere near the light path from the arc lamp or the projection lens.

Dangerous levels of ultraviolet and infrared radiation, dangerous glare, very high temperatures (180°C to 300°C) and high internal gas pressure are present at the Xenon Arc Lamp. The lamp is contained in a protective reflector-housing module and should not be operated outside this housing or outside of the projector.

When replacing the Arc Lamp, replace it as an entire module, as shown in this manual. Do not open the lamp housing or attempt to replace the Arc Lamp inside its module! Do not touch the Arc Lamp, or any connections, when the lamp is ignited or is arcing.

Any servicing of the Arc Lamp must remain restricted to Hughes-JVC Certified Technicians.

Before performing procedures in this chapter,

When performing procedures in this chapter

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Chapter 4---Optical

4.1 Arc Lamp

The Arc Lamp is the beginning of the high intensity Light Path. It is located inside a housing on the right side of the Optical Support Assembly (see Figure 4-5).

Arc Lamp - Main Functions:

The Arc Lamp is a single component composed of a Xenon gas bulb at the center of a compound elliptical reflector. It supplies the high intensity white light used by the projector to put a very bright image on the screen. The expected 50% life (half of initial light output) of an Arc Lamp is approximately 1000 hours.

Arc Lamp - Inputs

32 kV pulse to light the Arc Lamp Power Supply

2 kW constant power during normal operation

Arc Lamp - Operation

The Arc Lamp Power Supply and the Igniter Assembly work together to produce a 32 kV pulse that ignites the Arc Lamp. After the Arc Lamp lights, the voltage from the Arc Lamp Power Supply drops to a constant 25-31 volts at 70-85 amps. It will stay at this level during normal Arc Lamp operation.

Arc Lamp - Service Adjustments

When a new Arc Lamp is installed, it will need to be aligned using the Arc Lamp adjustment fixture located inside the Arc Lamp housing (see Figure 4-2).

Arc Lamp Adjustment Tools Needed

Large Flatblade screwdriver 4-mm Hex-head wrench

Equipment Needed

Minolta Illumination Meter T-1 or equivalent

To align the Arc Lamp:

1. Remove the front cover (see Section 6.1).

2. Loosen the spider lock down bolt (see Figure 4-4).

3. Power the projector ON and let it run for 15 minutes to stabilize.

4. Verify that the "Shutters on Hide" box is checked in the System-

Preferences menu, then use the RGB key and the HIDE key to hide Red

and Blue. This prevents light coming from the Red and Blue ILA

4-2

5. Open the fan door of the Arc Lamp Enclosure housing using the large Flatblade screwdriver to rotate the retaining screws 90° This gains access

to the three Arc Lamp alignment screws. The Arc Lamp fan disconnects when this door is opened.

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Chapter 4---Optical

CAUTION

Fan disconnection is acceptable for a short

period of time only (preferably <20 minutes--maximum 45 minutes).

WARNING!!!

Dangerous levels of ultraviolet and infrared radiation, dangerous glare, very high temperatures (180°C to 300°C) and high internal gas pressure are present at the Xenon Arc Lamp. Protect eyes from ultra violet light and infrared light by using X5 (375 to 700 nanometers), ANSI approved, shade goggles when actually working on the projector near the arc lamp source.

6. Access the "Shutters on Hide" box again from the System-Preferences

menu and uncheck the box, then use the RGB and HIDE keys to hide Green. This mutes video from the Green CRT but leaves the Green shutter

open to allow Arc Lamp light from the Green ILA

to display on the

screen.

7. Select ILA® Bias from the System-Factory Adjustments menu. Record the

current ILA® bias level. Return to this bias level when this adjustment is complete. Record only the Green ILA® bias value because Red and Blue will return to their original levels when Green is reset.

8. Use the up-arrow key and adjust the ILA® bias for Green for maximum

light output.

9. Adjust the Arc Lamp alignment screws (see Figure 4-2) to center the "hot

spot" (brightest area). Figure 4-1 illustrates a "hot spot" on the screen.

NOTE:

It is easier to perform the following procedure with one person

standing in front of the screen holding a light meter and another person making the adjustments to the Arc Lamp.

10. Use the light meter to locate the brightest area or “hot spot”, (see Figure

4-1). Move the light meter around the screen to determine where the hot spot is located. The “hot spot” will be where the light reading is highest.

11. Adjust screw 1, 2, or 3, (see Figure 4-2) to move the hot spot to the center

of the screen. Moving the “hot spot” will generally require adjusting two or more screws. Adjusting all three screws adjusts the Arc Lamp on the zaxis. Adjusting the three screws clockwise increases light output and rolloff.

12. Check for maximum brightness and readjust the z-axis as necessary after

setting the x-axis and again after setting the y-axis.

13. Tighten spider lock down bolt.

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Chapter 4---Optical

Hot spot off-center

Figure 4-1

Arc Lamp “Hot Spot” (brightest area) is off-center vertically and

horizontally. Adjust to center the “hot spot”.

Figure 4-2

Arc Lamp alignment fixture.

4-4

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Chapter 4---Optical

Figure 4-3

Arc Lamp Assembly access door.

Arc Lamp - Remove and Replace

The Arc Lamp Enclosure Assembly consists of the Xenon Arc Lamp module and blower. Replace the blower together with the Arc Lamp Module.

Tools Needed

7/16 inch wrench #1 Pozi-drive Phillips-head screwdriver Diagonal wire cutters (or equivalent)

Parts Needed

Arc Lamp p/n 106298

WARNING!!!

Dangerously bright light and high current exist in this area of the projector. Before proceeding with the removal of any subassemblies below, verify that the circuit breaker at the rear of the projector is turned off and the power plug is removed from the AC outlet.

To Remove the Arc Lamp:

Power off the projector by IR Remote or PC, and allow the cooling fans to run until they shut off.

Turn the AC Circuit Breaker to the OFF position but leave the AC Power Cord plugged in to maintain chassis ground.

Remove the front cover (see Section 6.1).

Disconnect the white Anode cable from the Igniter, using the 7/16-inch wrench (see Figure 3-7).

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Chapter 4---Optical

Disconnect the orange Cathode cable from the Igniter, using the 7/16-inch wrench (see Figure 3-7).

Cut the cable tie that is wrapped around the ferrite inductor (metal tube with white cap below the blower).

Disconnect the Arc Lamp door fan cable. This cable runs through the door and out the bottom of the Arc Lamp Assembly housing (below the right side inFigure 4-3). It provides power to the Arc Lamp door fan through the white socket shown to the right of the Arc Lamp fan in Figure 4-3. Disconnect the cable at the socket connection below the Arc Lamp housing. Disconnect the top fan cable.

Disconnect large blower fan connector.

Remove the FA shield from the top of the Arc Lamp. Three #1 Pozi-drive Phillips-head screws hold the FA shield in place (see Figure 4-4).

10.

Remove the two retaining bolts for the Arc Lamp, using a 10-mm socket and driver.

11.

Reverse the procedure to install the Arc Lamp. Check and adjust the Arc Lamp alignment after replacing. There is no Arc Lamp current adjustment.

4-6

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Chapter 4---Optical

Figure 4-4

Arc Lamp Assembly top view.

4.2 Optical Path

Optical Path - Main Function

Transports the Arc Lamp high intensity light from the Arc Lamp to the ILA® and from the ILA® to the Projection Lens

Removes the Infrared light that contains most of the heat

Removes the unwanted Ultraviolet light

Condenses the white light using the Light Pipe for a uniform output

Separates the white light into its RGB component colors using Dichroic Beamsplitters.

Polarizes each of the component RGB light beams

Combines the component RGB image beams into one beam and delivers that to the Projection Lens.

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Chapter 4---Optical

Figure 4-5

Upper level view of Optical Path (top view).

Optical Path - Inputs

Arc Lamp high intensity white light Component RGB Image light from each of the ILA

Optical Path - Outputs

Component RGB polarized light to the ILA

Output image light to the Projection Lens

Optical Path - Operation

The light travels from the Arc Lamp into the Optical Path (see Figure 4-5). The light reflects off a cold mirror and passes through a light pipe. From the Light Pipe, the light passes through a Condensing Lens .The Condensing Lens also acts as a XY Positioner. The function of the XY Positioner is to aim the light beam down the optical path and center it on the face of the ILA®.

After being positioned by the Condensing Lens, the light then reflects off two more Cold Mirrors, losing more Infrared light. It passes through another Condensing Lens and into the Dichroic Beamsplitter Assembly.

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Chapter 4---Optical

The Dichroic Beamsplitter Assembly separates the white light into its red, green, and blue components. Each component light beam goes into the Prism Assembly where it is polarized.

Light can be viewed as having two electromagnetic components: a Horizontalelectric field and a Vertical-electric field. These fields are perpendicular to each other. When unpolarized light travels through a polarizing beamsplitter, one of these fields is reflected and one is transmitted or passes through the beamsplitter. Upon striking the Prepolarizer, the Vertical field is reflected and is wasted, the Pelectric field is passed through the Prepolarizing Beamsplitter and continues on to the Main Polarizer. The Main Polarizing Beamsplitter (PBS) is rotated 90° from the Pre-Polarizing Beamsplitter so the Horizontal field that was transmitted through the Prepolarizer is reflected by the Main Polarizer. The reflected polarized light, either red, green or blue, leaves the PBS and goes directly into the ILA® (see Figure 4-6 and Figure 4-7).

Each color exits the Prism Assembly and enters an ILA® where the Liquid Crystal in the ILA® rotates the polarized light. The image light striking the input side of the ILA® modulates the polarized light. The image on the input of the ILA

originates as a image signal and is transformed into an image by the CRT. The image from the CRT passes through the Relay Lens and is focused onto the input side of the ILA®. The modulated image light leaves the output side of the ILA

and re-enters the Prism Assembly where all three colors combine in the 4P combining optic. The image light exits the Prism Assembly, passes through the Projection Lens, and is projected out on the screen (see Figure 4-7).

WARNING!!!

Wear safety goggles (rated X5) when working anywhere near the light path from the arc lamp or the projection lens. DO NOT open any of the Optical Support Assembly covers while the projector is ON. The bright light can cause severe eye damage.

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Chapter 4---Optical

4-10

Figure 4-6

Optical Path

Model 250 Service Manual

Chapter 4---Optical

Figure 4-7

Optical Path

Optical Path - Service Adjustments

Tools Needed

3-mm Hex wrench

Parts Needed

No serviceable parts

The one adjustment that can be performed on the optical path is with the XY Positioner that moves the #1 Condensing Lens in the X- and Y-axis. The XY

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Chapter 4---Optical

Positioner adjusts the light beam coming out of the Light Pipe so that it projects squarely onto the face of the ILA®.

NOTE:

Do not adjust the XY Positioner unless there is a dark edge visible on

screen. If the XY Positioner is misaligned, there will be a dark edge on the left, right, top

or bottom edge caused by the edge of the Light Pipe. Perform the Arc Lamp alignment before adjusting the XY Positioner unless the dark edge makes Arc Lamp alignment difficult or impossible.

To adjust the XY Positioner:

1. Turn the projector ON and allow it to stabilize for at least 15 minutes.

2. Check the screen for dark edges on the top, bottom, left, or right. Check

the screen with all three colors, using the Variable Flat Field (test pattern #4) or with ILA® bias only. The dark edge will be obvious in either mode.

3. Remove the front cover.

4. There are four access holes; two with small notches on the top of the hole

and two without notches (see Figure 4-8). Use the two access holes without notches. These holes are for full aperture ILA®s. The upper access hole is for vertical adjustment; the lower one is for horizontal adjustment.

5. Insert a 3-mm (long shank) Hex-head wrench into either the horizontal or

vertical access hole and adjust the XY Positioner until the dark edge moves off the screen.

4-12

Figure 4-8

XY Positioner adjust holes.

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Chapter 4---Optical

4.3 ILA

ILA® Main functions

ILA® Inputs

Arc Lamp light - High intensity polarized Red, Green or Blue light from the Prism Assembly.

Image light - Red, Green, or Blue image light from the CRTs. ILA® Bias Voltage and Frequency - 10-13 Vac at 2 kHz

ILA® Outputs

Modulates image light from the CRT onto the high intensity polarized light from the Arc Lamp

Reflects high intensity light received from the Prism Assembly back into the Prism Assembly after modulating with image light

Adjustable bias voltage and frequency (ILA® Sensitivity)

Adjustable offstate with Super Contrast ILA®s

Image light from CRT is blocked from output. Image is electrostatically coupled to output

Image light - High intensity polarized image light output to the Prism Assembly and then to the Projection Lens and screen.

Figure 4-9

ILA® structure

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Chapter 4---Optical

ILA® Operation

The ILA® plays a critical part in bringing the image to the screen. The ILA receives the image light when the CRT projects the image through the Relay Lens and focuses it onto the photoconductive layer on the input side of the ILA®. The image does not pass directly through the ILA® but is transferred by a change of impedance of the photoconductive layer to the Liquid Crystal Layer on the output side of the ILA®. The light coming from the Arc Lamp enters the output side of the ILA® and passes through the Liquid Crystal layer. Here the polarized light is rotated according to the orientation of the liquid crystal molecules. It then reflects off the mirror and passes back through the liquid crystal layer. The polarized light it is rotated again and then exits the ILA®. The amount the liquid crystal rotates the polarized light depends on the ILA® Bias, ILA® Sensitivity (frequency), and CRT brightness (Sensitivity and Threshold).

Service Adjustments

ILA

ILA® Bias and Sensitivity Adjustment The ILA® has adjustable bias and frequency (sensitivity). The ILA® bias and

sensitivity are adjusted by software through the menu (see Model 250 User’s Guide, section 5.6 Setup Adjustments). The ILA® bias is individually adjustable for each ILA®; the ILA® sensitivity (frequency) adjusts all the ILA®s together.

Super Contrast ILA® Compensator Adjustment The offstate level can be adjusted on Super Contrast ILA®s. The Compensator

adjustment moves a lever on the top of each Super Contrast ILA® to a null position. The null position is where the offstate level is as dark as possible. The Compensator is set at the factory and should not need adjustment. Perform this procedure when replacing an ILA® assembly or if the Compensator adjustment lever has been inadvertently moved.

To set the Super Contrast ILA® Compensator:

1. Power the projector ON and allow it to stabilize for at least 30 minutes.

2. Remove the rear cover and tilt the Electronics Module up.

3. Under the System-Preferences menu, verify that the "Shutters on Hide"

box is checked.

4. Use the HIDE key to hide red and blue.

5. Disconnect the connector from the top of the green ILA

6. Move the Compensator lever (this lever is just in front of the ILA

assembly.

connector) to the right and left until the darkest level appears on the screen.

7. Reconnect the ILA

8. Repeat the above steps for the red ILA

connector to the green ILA®.

and blue ILA®. Block the light

from the other two ILA®s each time, using the HIDE key.

4-14

9. Replace the rear cover.

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Chapter 4---Optical

NOTE:

Reset the ILA® bias after setting the Compensator and check G

Sensitivity Offset, and Threshold Offset level (see Model 250 User’s

Guide, section 5.8 Black Level G2 and Sensitivity Offset). ILA® Overlap This adjustment positions the ILA® assemblies in their sockets so that the image

from each ILA® will overlap (be placed on top of) the other two ILA®s. Make this adjustment whenever replacing an ILA®.

Tools Needed

4-mm hex-head wrench Flathead screwdriver

Parts Needed

No parts are needed

To determine if this adjustment is necessary:

1. Power the projector ON and allow it to stabilize for at least 30 minutes.

2. Record the value of the ILA® bias for red, green and blue. Return the

ILA®s to these levels when this procedure is complete.

3. Under the System-Preferences menu, verify that the “Shutters on Hide”

box is unchecked.

4. Use the HIDE key to hide red, green and blue.

5. Increase the ILA® bias for all three colors to maximum. The image on the

screen should be white with some colors at the edges.

6. Check the right, left, top, and bottom edges of the images on the screen.

Using the green image as a reference, compare the edges of the red and

blue image to the green image.

NOTE:

If the green ILA® has been replaced, reference green to the blue or

red image.)

8. If there is a red or blue border on the left, right, top or bottom edge, the

s overlap and need adjustment. If both the red and blue overlap, the

ILA

border will be yellow. In either case, proceed with the adjustment below.

9. If there is no overlap, reset the ILA® biases to their previous levels from

Step 1. To perform an ILA

Overlap adjustment:

10. Continue with all three colors hidden.

11. Loosen the two wing nuts at the top of the ILA

assembly (see Figure

4-10).

12. If the overlap is at the left or right, grasp the ILA

assembly and slide it to the right or left so that the edges coincide with the edges of the other two ILA® assemblies.

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Chapter 4---Optical

To avoid damaging the connector,

not

the connector at the top.

grasp the ILA

Figure 4-10

CAUTION!

assembly itself,

ILA® Assembly top view. The overlap screws shown are under

the ILA®. They are visible only after the ILA® assembly is removed.

13. If the overlap is at the top or bottom, be sure the projector is level. Slide

the spring clip (see Figure 4-10) at the top of the ILA® assembly back.

14. Loosen the two hex nuts, using a 4-mm hex-head wrench.

WARNING

!!!

Always wear an ANSI/ASTM 10,000 volt rated safety glove when working around CRTs due to the High Voltage present there.

15. Slide the ILA®/Relay Lens/CRT Assembly back and remove the ILA

assembly (it will slide out with some resistance).

16. There are two adjustment screws at the bottom of the ILA® assembly that

move the ILA

up or down. Turn these screws in or out very slightly to

allow the ILA® to seat lower or higher, as necessary.

17. Reinstall the ILA

assembly, slide the ILA®/Relay Lens/CRT Assembly

forward and replace the spring clip.

18. Repeat Step 4 as necessary.

4-16

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Chapter 4---Optical

19. Retighten the two wing nuts and tighten the two hex nuts.

20. Reset the ILA® biases to their previous levels from Step 2.

ILA® Back Focus Adjustment The ILA® Back Focus adjustment moves the ILA®/Relay Lens/CRT assemblies

forward or backward as one unit to focus the ILA® output on the screen. When using a zoom lens this adjustment allows the zoom lens’ tracking to remain focused on the screen throughout the entire zoom range. Use the Focus Pattern (Test Pattern #6) to perform this adjustment one color at a time. The procedures below perform the ILA® Back Focus for the Green lens. The first procedure is for a zoom lens. The second procedure is for a fixed lens.

For best results, perform ILA® Back Focus procedure with two people: One person to stand in front of the screen to observe Spacer Balls and the other to move the ILA®/Relay Lens/CRT assemblies back and forth. This is a factory-set adjustment, but may need some touch-up in the field.

Tools Needed

4-mm Hex wrench

2.5-mm Hex wrench

Parts Needed

No parts are needed

To adjust the ILA® Back Focus for a Zoom Lens:

1. Power the projector ON and allow to stabilize for at least 15 minutes

2. Remove the Rear Cover and tilt up the Electronic Module.

3. Hide Red and Blue. View Green.

4. Select the Focus Pattern (Test Pattern #6).

5. Select Projection Lens from the menu.

6. Use the up/down arrow keys to zoom the Projection Lens to full telephoto

position (smallest image).

7. Use left and right arrows to focus the projection lens to get sharply

focused spacer balls.

NOTE:

Spacer balls separate the layers inside the ILA

Assembly. They are tiny, random, irregularly shaped spots that are visible throughout the image. Stand directly in front of the screen and look in the lighter areas of the image to see the Spacer balls. From throw distances shorter than 4 meters, spacer balls are difficult to see.

8. Zoom the lens to a wide-angle position (largest image).

9. Loosen the wing nut on the Green Relay Lens (or whichever lens is being

focused).

Model 250 Service Manual 4-17

Chapter 4---Optical

WARNING!!!

Always wear an ANSI/ASTM 10,000 volt rated safety glove when working around CRTs due to the High Voltage present there.

NOTE:

If the ILA®/Relay Lens/CRT assembly cannot be moved close enough to get a good spacer ball focus, loosen the CRT Lens Stopper Ring in front of the CRT Holder Ring using a 2.5-mm Hex wrench. Move the CRT snug against the collar to get additional range, and then, retighten the collar.

10. Using the 4-mm hex-head wrench, loosen the two hex bolts (see Figure

4-10) on the ILA® assembly in front of the Relay Lens.

11. Slide the Relay Lens/CRT/ILA® assembly forward or backward to achieve

the sharpest spacer ball focus.

NOTE:

Do not use the zoom lens focus while performing this step.

12. Repeat Steps 6-11 until the spacer balls stay in focus through the entire

zoom range. The spacer balls may go slightly out of focus in spots while zooming up or down, but they should be in focus at the smallest and largest images.

13. Tighten the hex bolts on the Green ILA® Assembly and the wing nut on

the Green Relay Lens.

14. Repeat Steps 9-13 for other colors that need ILA® Back Focusing. Be sure

to hide the other two colors.

To adjust the ILA® Back Focus for a Fixed Lens:

1. Power the projector ON and allow it to stabilize for 15 minutes.

2. Remove the rear cover and tilt up the Electronic Module.

3. View Green. Hide Red and Blue.

4. Select the Focus Pattern (Test Pattern #6).

5. Select Projection Lens from the menu.

6. Use left and right arrows to focus the projection lens to get sharply

focused spacer balls.

7. Put on safety gloves (see Safety section for gloves type) then loosen the

wing nut on the Green Relay Lens, (or whichever lens is being focused).

NOTE:

If the ILA®/Relay Lens/CRT assembly cannot be moved close enough to get a good spacer ball focus, loosen the CRT Lens Stopper Ring in front of the CRT Holder Ring using the 2.5-mm Hex wrench. Move the CRT snug against the collar to get additional range, then retighten the collar.

4-18

Model 250 Service Manual

Chapter 4---Optical

8. Loosen the two hex bolts (see Figure 4-10) on the ILA® assembly in front

of the Relay Lens.

9. Slide the Relay ILA®/Lens/CRT assembly forward or backward to achieve

the sharpest spacer ball focus.

NOTE:

Do not use the projection lens focus while performing this step.

10. Tighten the hex bolts on the Green ILA® Assembly and the wing nut on

the Green Relay Lens.

11. Repeat Steps 7-10 above for other colors that need ILA® Back Focusing.

Be sure to hide the other two colors.

ILA® Remove and Replace

Each projector has three ILA®s; each located on the front of a Relay Lens. Tools Needed

4-mm Hex wrench

Parts Needed Super Contrast

Blue 102630-14 Green 102630-15 Red 102630-16

NOTE:

Do not interchange Super Contrast ILA®s. The Compensators on the ILA®s are color specific and can not be interchanged i.e. the green ILA® can not be put in the red channel or blue channel.

To Remove the ILA

It is not necessary to power off the projector.

Remove the Rear cover. It is not necessary to tilt the Electronics Module up.

Loosen the two Hex nuts using a 4-mm Hex nut wrench and slide the

/Relay Lens/CRT Assembly back.

ILA

Loosen the two wing nuts on the ILA® and pull back the spring clip.

Disconnect the connector from the ILA® and remove the ILA® assembly (it will slide out with some resistance).

It will be necessary to reset ILA

bias, and Overlap. ILA® Compensator, G

setting, and shading for the ILA® being replaced should be checked.

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Chapter 4---Optical

4.4 Relay Lenses

The Relay Lens focuses the image light received from the CRT on the photoconductive layer of the ILA® (see Figure 4-9). There are no service adjustments for the Relay Lens. The Relay Lens rarely needs service and is not considered a serviceable part.

4.5 Projection Lens

Projection Lens - Input

Combined RGB image light from the Prism Assembly.

Projection Lens - Output

Output image light to the screen

Projection Lens - Operation

The projection lens receives image light from the Prism Assembly. The light is high intensity light from the ILA® that has been modulated by the image light from the CRT. After leaving the ILA®s the modulated light travels back through the Prism Assembly where the red, green, and blue image light are combined. The Projection Lens focuses this output image light onto the screen. All Projection Lenses come with motorized focus adjustment.

The Model 250 projector comes with a choice of four standard lens options. Motorized Zoom Lens

2:1 - 4:1

Fixed Lenses

0.96: 1

1.5: 1

5.6:1

Optional Lenses

2.4:1 Simulator Lens

Projection Lens - Service Adjustments

There are no service adjustments for the Projection Lens. The focus adjustment, both rough and fine focus adjustments, are part of the projector setup procedure (see Model 250 User’s Guide, Setup Adjustments sections 5.4 and 5.5.15)

Projection Lens - Remove and Replace

Tools Needed

5-mm Hex wrench

To remove the Projection Lens:

Remove the sponge cover that is around the front of the Projection Lens.

4-20

Disconnect and label the Projection Lens Focus and Zoom motor cables (The Focus motor is at the top of the Projection Lens. The Zoom motor is at the bottom.)

Model 250 Service Manual

Chapter 4---Optical

Loosen (do not remove) the Lens holding screw at the right side (see Figure 4-11) of the Projection Lens.

Figure 4-11

NOTE:

Projection Lens holding screw and removal notch.

The 0.96:1 Projection Lens has an adapter sleeve installed on it. The Projection Lens is installed the same as other Projection Lenses except the Holding Bolt needs to be loosened more to allow the Projection Sleeve to clear it.

Rotate the Projection Lens left or right as needed so that the notch on the lens clears the holding screw on the lens holder (see Figure 4-11).

Carefully pull the Projection Lens out of the projector.

Replace the Projection Lens in reverse order. Be sure to reconnect the Zoom and Focus motor cables.

NOTE:

Use the same procedure to install or remove fixed lenses. Also,

when changing from a zoom to a fixed lens, or vice versa, check the ILA Back Focus adjustment (see section 4.3 ILA®).

Model 250 Service Manual 4-21

Chapter 5 Optical

3-4-22

Model 100 Service Manual

5.0 Electronics

Contents

5.1 Safety............................................................................................................ 5-1

5.2 Introduction.................................................................................................. 5-2

5.3 System Controller PCB................................................................................5-3

5.4 Video Processor PCB................................................................................... 5-11

5.5 Raster Timing Generator PCB ..................................................................... 5-16

5.6 Horizontal Vertical Deflection PCB ............................................................5-21

5.7 Convergence Deflection PCB ...................................................................... 5-28

5.8 Scan Reversal PCB.......................................................................................5-34

5.9 Video Amplifier PCB................................................................................... 5-43

5.10 CRT/Yokes.................................................................................................. 5-51

5.11 VICs ............................................................................................................ 5-58

Standard RGBHV VIC...............................................................................5-59

Graphics Enhancer Plus VIC......................................................................5-61

4-Input (Quad) RGBHV VIC..................................................................... 5-64

YPbPr VIC ................................................................................................. 5-67

Quad Standard Decoder VIC...................................................................... 5-70

Quad Standard Decoder/Line Doubler VIC............................................... 5-72

5.12 Backplane PCB .......................................................................................... 5-74

Chapter 5---Electronics

5.1 Safety

review the chapter on Safety at the beginning of this manual

that require projector covers to be removed, wear high voltage gloves (ANSI/ASTM 10,000 volt rated) when working near the CRTs, Arc Lamp, or power supplies. Wear safety goggles (rated X5) when working

anywhere

CAUTION

WARNING!!!

near the light path from the arc lamp or the projection lens.

Before performing procedures in this chapter,

When performing procedures in this chapter

Model 250 Service Manual 5-1

Chapter 5---Electronics

WARNING

lighted Projection Lens or into the lamp housing, from any distance, when the projector is on. Direct exposure to light of this brightness can cause severe eye injury.

5.2 Introduction

The Model 250 Electronics System includes nine printed circuit assemblies. They provide all the controlling voltages and signals to adjust and correct picture settings, geometry, convergence, and shading (see Chapter 4 of the User’s Guide). The Electronics System also controls video and sync input signals, LED displays on PCBs at the rear and side of the projector, two RS-232 communications ports, and two IR receivers for remote control of the projector.

The descriptions in this portion of the manual are based on an overall Electronics System block diagram and simplified block diagrams for each of the nine printed circuit assemblies.

!!!

Never look directly at the Arc Lamp, the

Figure 5-1 provides an overall System Block Diagram to show how the Optical System, Arc Lamp, and Electronics System combine to provide the bright screen image.

Figure 5-1

5-2 Model 250 Service Manual

Model 250 System Block Diagram.

Chapter 5---Electronics

Figure 5-2

data be downloaded (

Model 250 Electronics Module with PCBs (side view).

CAUTION

It is very strongly recommended tha t setup

Exported, see section 8.2 Importing/Exporting

performing any of the following procedures. Exporting baseline source setup data to disk is an excellent precautionary measure. It will save the

time of setting up new source file(s) in the case of an unexpected problem

5.3 System Controller PCB

System Controller PCB - Main Function

Enables control for the Low Voltage Power Supply, Arc Lamp and cooling fans.

Fault monitors the HVPS, LVPS, Arc Lamp, and fans.

Provides IIC serial bus communication and control between PCBs.

Controls Zoom and Focus of the Projection Lens.

Generates Menu and Internal Patterns Overlays

) before

X and Y Convergence control

Threshold and Sensitivity for shading

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Chapter 5---Electronics

I/O control for VIC selection

Two RS-232 serial interface ports

Infrared (IR) remote control interface. Accepts input from front or rear IR detectors.

External 3 color system status LEDs. Green indicates normal, yellow is standby and red indicates a fault condition.

External Service Mode Switch. Pressing this switch during a power-up sequence brings the system up in a diagnostic mode (for maintenance) rather than a normal operating mode.

Figure 5-3

Rear of Electronics Module with rear cover and panel removed.

5-4 Model 250 Service Manual

Chapter 5---Electronics

Figure 5-4

Model 250 Service Manual 5-5

System Controller PCB I/O Diagram for Power Supplies and peripherals.

Chapter 5---Electronics

Figure 5-5

System Controller PCB I/O Diagram for other PCBs.

System Controller PCB - Inputs

/LV_OK - signal from the Low Voltage Power Supply; it tells the System Controller PCB that all the non-standby supply voltages are working.

/HV_OK - signal from the High Voltage Power Supply; it tells the System Controller PCB that all the high voltage supplies are working.

/LAMP_OK - signal from the Arc Lamp Power Supply. /LAMP_LIT - signal from the Arc Lamp Power Supply; it tells the System

Controller PCB that the Arc Lamp is lit. ODD_FIELD - Square wave signal from the Raster Timing Generator PCB, with

50% duty cycle that is low during odd fields of an Interlace signal. This signal is high during noninterlaced signals.

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Chapter 5---Electronics

280_CLK - Square wave signal from the Raster Timing Generator PCB, with 50% duty cycle, synchronized to the horizontal sync at 280 times the frequency of the horizontal sync. This signal is used by the System Controller PCB to properly output shading and convergence data.

SOURCE_VALID - Signal from Raster Timing Generator PCB indicates a new source (or valid source). A high indicates a valid stable signal and a low indicates a change in input signal.

H_DRIVE - Square wave signal from Raster Timing Generator PCB, with a 50% duty cycle synchronized to the selected horizontal sync.

V_DRIVE - Square wave from Raster Timing Generator PCB, with a negative going pulse synchronized to selected vertical sync with a pulse width of about four horizontal lines.

/FRONT_IR - command signals from the front infrared receiver. /REAR_IR - command signals from the rear infrared receiver H_F2V - DC voltage from the Raster Timing Generator PCB, proportional to the

horizontal frequency of the current source. IIC CLK - IIC clock line, unidirectional clock line for control of synchronous data

transfer of data between PCBs. IIC DATA - IIC data line, bi-directional serial data line for control of

synchronous data transfer between the System Controller PCB and the Raster Timing Generator PCB.

+5.1 V Stdby - from the Low Voltage Power Supply when the AC Circuit Breaker is turned on; it supplies power to the CPU, Interlock Switches, and IR Detectors before the projector receives the POWER ON command.

+5.1 V - from the Low Voltage Power Supply for all digital circuitry. ±15 V - from the Low Voltage Power Supply for all analog circuitry GND - Ground

System Controller PCB - Outputs

/LV_ENA - signal to enable the Low Voltage Power Supply non-standby voltages after the System Controller PCB receives the POWER ON command.

/FAN_ENA - signal to the Low Voltage Power Supply to turn on the +24 V stby supply to turn on the cooling fans.

/LAMP_ENA - signal to enable the Arc Lamp Power Supply. RGB_OVER - signal to Video Processor PCB for the On-screen Menu and /or

Internal Test Pattern for red, green, and blue. OVERLAY - signal to the Video Processor PCB, to switch between internal and

external sources.

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Chapter 5---Electronics

RGB_THRES - red, green, or blue Threshold correction information to the Video Processor PCB.

RGB_SENS - red, green, or blue Sensitivity correction information to the Video Processor PCB.

ISYNC - 5 MHz clock to the Raster Timing Generator PCB, used to generate the internal sync signals

Y_RGB_CONV - control signals to Convergence Deflection PCB for Red, Green, or Blue Convergence in the y-axis (full-scale correction is about 1 Vpp).

X_RGB_CONV - control signals to Convergence Deflection PCB for Red, Green, or Blue Convergence in the x-axis (full-scale correction is about 1 Vpp).

CORR_SYNC - Square wave HCT level synchronous signal to the Convergence Deflection PCB for the horizontal axis.

RGB_SHUT - Signal to operate the red, green, and blue shutters. LENS_ZOOM - Signal to the zoom motor of the Projection Lens. LENS_FOCUS - Signal to the focus motor of the Projector Lens.

System Controller PCB - Operation

Startup Functions When AC Circuit Breaker is powered ON, the Low Voltage Power Supply sends

+5.1 V stdby voltage to the System Controller PCB. The +5.1 V Stdby powers the CPU and IR Detector so the System Controller PCB can receive and respond to the POWER ON command. The System Controller PCB sends a /FAN_ENA signal back to the LVPS turning on the +24 V Stdby to turn the cooling fans on. When the System Controller PCB receives a POWER ON command from either the IR remote control or a PC, it sends the /LV_ENA signal to the Low Voltage Power Supply. This turns on all the non-standby (±15 V, +5.1 V, +6.2 V, +24 V, +80 V) voltages. After all the non-standby voltages power up, the LVPS sends the /LV_OK signal back to the System Controller PCB to tell it that all the nonstandby voltages are present.

When the System Controller PCB receives a POWER ON command, it receives the /LAMP_OK signal from the Arc Lamp Power Supply and sends the /LAMP_ENA signal back to the Arc Lamp Power Supply to turn it on. The Arc Lamp lights, and the Arc Lamp Power Supply sends a /LAMP_LIT signal back to the System Controller PCB (see Figure 5-6).

The System Controller PCB also monitors the status of the High Voltage Power Supply through the /HV_OK signal.

5-8 Model 250 Service Manual

Chapter 5---Electronics

Figure 5-6

Power On timing sequence. Normal Operation Functions During normal projector operation, the System Controller PCB receives

commands through the remote control, tethered remote control, or a PC. Commands issued from the IR remote controls are received through IR Detectors located on the front and rear of the projector. Commands issued from a PC, Laptop, or Tethered Remote Control are received through the RS-232 serial interface ports.

The two RS-232 ports, labeled Terminal-in and Control-out, are functionally almost identical. Both ports can be used to interface with computers, switchers, or other remote controlling devices using a null modem cable. The difference is, importing and exporting of configuration data can only be performed through the Terminal-in. The dipswitch on the back of the System Controller PCB controls the baud rate (see Figure 7-2).

The System Controller PCB enables the Video Processor PCB to select between an internal and external source through the OVERLAY signal. The System

Model 250 Service Manual 5-9

Chapter 5---Electronics

Controller PCB also enables the selected VICs through the IIC bus based on the VIC selected on the Channel Menu.

The System Controller PCB generates the on-screen menus and test pattern overlays and sends them to the Video Processor PCB. It sends the X and Y Convergence correction data to the Convergence Deflection PCB. It sends Threshold and Sensitivity shading data to the Video Processor PCB for the all three colors. The System Controller PCB stores all the configuration data such as Geometry, Convergence, Shading, ILA® Bias and Sensitivity, and G2 settings etc. in flash memory and allows that data to be exported to, or imported from a floppy disk.

The System Controller PCB displays system status through a single three-color LED visible on the back panel. A green light indicates normal operation, the yellow indicates standby operation, and red indicates a fault or error condition.

The System Controller PCB has an External Service Mode Switch that enables the operator to switch from the normal operating mode to a diagnostic mode. If there is a new release of system software, it can be uploaded into the projector by switching into the diagnostic mode. The procedure for this is in the Software and Protocol section (see Chapter 8, Software and Protocol).

System Controller PCB - Remove and Replace

Tools Needed

#1 Pozi-drive Phillips-head screwdriver #0 Pozi-drive Phillips-head screwdriver

Parts Needed

System Controller PCB - p/n 104678

To remove the System Controller PCB:

Power OFF the projector by IR Remote or PC, and allow the cooling fans to run until they shut off automatically.

Turn the AC Circuit Breaker to the OFF position and unplug the AC Power Cord.

Disconnect all the external source video cables and control cables.

Remove the rear cover.

Remove the Back Panel. Remove the nine Pozi-drive Phillips-head retaining screws using the #1 Pozi-drive Phillips screwdriver.

Remove the Connector Bracket by removing the single Pozi-drive Flathead Phillips-head screw using the #0 Pozi-drive Phillips screwdriver.

Pull the black Card Extractor handles back to disconnect the System Controller PCB connector and pull the PCB out of the Electronics Module.

Reverse the procedure to install the System Controller PCB.

5-10 Model 250 Service Manual

5.4 Video Processor PCB

Video Processor PCB - Main Functions

Video signal input and multiplexing

Sync signal stripping

Overlay signal multiplexing

Brightness, Contrast, DC Restore and Blanking

Video signal gamma correction

Sensitivity and Threshold signal input and control

Automatic Contrast, G2, and internal image limiting

Video Processor PCB - Inputs

RGBHV VIC 1,2, & 3 - External image signals from the VICs for red, green, and blue.

/SEL_VIC - input signal from the RGB VIC used to select the input source from VIC #1.

Chapter 5---Electronics

RGB_OVER - from the System Controller PCB, the Menu overlays and internal test patterns for red, green, and blue.

OVERLAY - from the System Controller PCB, switches between internal and external sources.

CLAMP - Pulse signal from the Raster Timing Generator PCB, tells the Video Processor PCB the timing and duration of the DC Restore.

BLANKING - Pulse signal from the Raster Timing Generator PCB, it tells the Video Processor PCB the blanking interval during the scan.

RGB_THRESH - Threshold correction information for red, green, or blue from the System Controller PCB. Real time data at 0-1 V.

RGB_SENS - Sensitivity correction information for red, green or blue from the System Controller PCB. Real time data at 0-1 V.

RGB_BEAM - sense signal proportional to the cathode current averaged over several horizontal lines in the red, green, or blue CRT. The voltage level is + mV/mA.

/VA_OK - signal from the Video Amplifier PCB telling the Video Processor PCB the Video Amplifier PCB is receiving red, green, and blue deflections voltages from the Horizontal Vertical Deflection PCB.

IIC_DATA - IIC data line. Bi-directional serial line for synchronous data transfer between the System Controller PCB and Video Processor PCB.

IIC_CLK - IIC clock line. Unidirectional clock line for control of synchronous data transfer over IIC bus.

Model 250 Service Manual 5-11

Chapter 5---Electronics

Figure 5-7

5-12 Model 250 Service Manual

Video Processor PCB I/O diagram for VICs and Power Supplies.

Chapter 5---Electronics

Figure 5-8

Video Processor PCB I/O diagram for PCBs.

Video Processor PCB - Outputs

RGB_VID - red, green, or blue video signal to Video Amplifier PCB, typically 01 V.

H&V_SYNC - horizontal sync pulse goes to the Raster Timing Generator PCB. GRN_SYNC - sync-on-green sync pulse goes to the Raster Timing Generator

PCB. RESTORE - DC Restore control signal to the Video Amplifier PCB. This signal

controls the DC level of the image signal, clamping it to the proper level on the Video Amplifier PCB.

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Chapter 5---Electronics

RGB_G2 - red, green, or blue G2 voltage adjust control signal to the Video Amplifier PCB.

G1_BIAS - G1 adjust control voltage (global adjustment) to the Video Amplifier PCB.

IIC_INT - IIC interrupt output to System Controller PCB.

Video Processor PCB - Operation

The Video Processor PCB accepts image and synchronizing inputs in either composite or separate RGBHV component format from the selected VIC. When the projector receives the power ON command, the System Controller PCB polls the VICs to determine what VICs are available. It then activates the VIC selected in the Channel Menu (see section 4-6 in the User’s Guide). The selected VIC sends a signal (/SEL_VIC) to the Video Processor PCB telling it which VIC is active.

The Video Processor separates the sync pulses and passes them (H_SYNC and V_SYNC) on to the Raster Timing Generator PCB. If the source sync type is Sync-on-Green, the Video Processor strips the horizontal and vertical syncs from the green input and sends that sync signal (G_SYNC) to the Raster Timing Generator PCB.

The Video Processor PCB adjusts the image input information with contrast, brightness, DC restore clamp, and blanking. Contrast changes the peak to peak amplitude of the External image while keeping the offset (black level) the same. Brightness shifts the DC level of the External image up or down while keeping the peak to peak amplitude the same. The DC restore circuit (or clamp pulse) restores the DC offset (black level) after each horizontal line. Contrast and Brightness commands come from the IIC data bus. The DC Restore and Blanking signals come directly from the Raster Timing Generator PCB.

The Video Processor PCB switches in the menu overlays and internal test patterns. It performs gamma correction adjustments, and applies the shading (sensitivity and threshold) adjustments. The menu overlay signals create the displayed menus and test patterns. Menu overlays are generated on the System Controller PCB. The gamma circuit corrects non-linearities, primarily due to the

. Gamma correction consists of degrees of black and white boost. The

ILA gamma tracking controls adjust the gain of the image information near the 50% level.

Sensitivity and Threshold are shading adjustments that correct for non-uniformity in the CRT and ILA

. Sensitivity adjusts the gain (same as Contrast only local instead of global) and threshold adjusts the DC offset (black level) (same as Brightness, only local instead of global) to adjust the dark areas of the red, green, or blue channel. The sensitivity and threshold commands come from the System Controller PCB through the IIC bus and adjust both the internal and external image information. Sensitivity and Threshold are applied to the image information after the contrast, brightness and gamma correction.

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Chapter 5---Electronics

The G2 voltage accelerates the electrons that are emitted from the cathode of the CRT. The CRT filament emits the electrons and G1 voltage regulates the amount of electrons that are emitted from the cathode. The G2 voltage is adjusted through the menu (Black Level). The Video Processor PCB receives the G2 control data for each color through the IIC bus and sends an analog voltage to the Video Amplifier PCB to control the G2 voltage.

The Video Processor PCB protects the CRTs from excess beam currents to prevent it from burning the phosphor. The Video Amplifier PCB sends a sample of the beam current (RGB_BEAM) for each CRT back to the Video Processor PCB. The Video Processor PCB compares this sample to a preset value. If the sample beam current is higher than the preset value, the Video Processor PCB reduces the contrast for the CRT with high beam current. If the CRT beam current is still high, it then reduces the G2 voltage. The maximum beam current is 250 µA per CRT.

The Video Processor PCB receives the G1_BIAS signal from the System Controller PCB through the IIC bus and sends a voltage to the Video Amplifier PCB to set the brightness level.

Figure 5-9

Video Processor PCB LEDs.

Video Processor PCB - Remove and Replace

Tools Needed

#1 Pozi-drive Phillips-head screwdriver

Parts Needed

Video Processor PCB - p/n 105234

To remove the System Controller PCB:

1. Power off the projector by IR Remote or PC, and allow the cooling fans to

run until they shut off automatically.

2. Turn the AC Circuit Breaker to the OFF position and unplug the AC

Power Cord.

3. Disconnect all the external source video cables and control cables.

4. Remove the rear cover.

5. Remove the Back Panel by removing the nine Pozi-drive Phillips-head

retaining screws using the #1 Pozi-drive Phillips screwdriver.

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Chapter 5---Electronics

6. Pull the black card extractor handles back to disconnect the Video

Processor PCB connector and pull the PCB out of the Electronics Module.

7. Reverse the procedure to install the Video Processor PCB.

5.5 Raster Timing Generator PCB

Raster Timing Generator PCB - Main Functions

Generates an internal sync pulse

Detects and selects sync pulses

Generates a phase locked sync

Generates blanking pulse

Provides horizontal and vertical phase adjustments

Detects interlaced and generates odd field pulse

Selects horizontal frequency band

Generates horizontal line count and vertical count

Provides IIC interface

Generates clamp pulse

Detects changes in source

Generates HVPS_SYNC signal

Enables horizontal deflection (/H_ENA) circuitry

Figure 5-10

Raster Timing Generator I/O diagram for Power Supplies.

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Figure 5-11

Raster Timing Generator for other PCBs.

Raster Timing Generator PCB - Inputs

V_SYNC - input vertical sync from the Video Processor PCB. H_SYNC - input horizontal sync from the Video Processor PCB. G_SYNC - Sync-on-Green sync stripped from green video signal at the Video

Processor PCB. ISYNC - 5 MHz clock from the System Controller PCB used to generate the

internal sync.

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IIC_CLK - IIC clock line. Unidirectional clock line for control of synchronous data transfer over the IIC bus.

IIC_DATA - IIC data line. Bi-directional serial line for synchronous data transfer between System Controller PCB and Raster Timing Generator PCB.

+15 V (two inputs) - input power from LVPS for analog circuitry including the Phase Lock Loop (PLL) circuit.

-15 V (two inputs) - input power from LVPS for analog circuitry including the Phase Lock Loop (PLL) circuit.

+5.1 V - input power from the LVPS for digital circuitry

Raster Timing Generator PCB - Outputs

SOURCE_VALID - signal to the System Controller PCB, indicates a new or valid source. High = valid, stable source, low = change in input source.

ODD_FIELD - square wave to System Controller PCB, with 50% duty cycle that is high during the odd field of an interlaced signal and low for non-interlaced signals.

280_CLK - square wave to System Controller PCB, with 50% duty cycle, synchronized to the horizontal sync at 280 times the frequency of the horizontal sync. This signal is used by the System Controller PCB to properly output shading and convergence data.

CLAMP - a negative-going image clamp signal to the Video Processor PCB, with about 3% duty cycle.

BLANKING - right, left, top, and bottom blanking signal to the Video Processor PCB.

H_BAND(0-3) - horizontal frequency band lines to the Horizontal Vertical Deflection PCB.

Band 0 = 15 - 24 kHz Band 1 = 24 - 28 kHz Band 2 = 28 - 55 kHz Band 3 = 56 - 90 kHz

/H_ENA - enables the horizontal deflection amplifier on the Horizontal Vertical Deflection PCB, Low = enabled deflection; high = disabled deflection.

H_FV2 - a DC voltage to the Horizontal Vertical Deflection PCB and System Controller PCB, proportional to horizontal frequency.

H_DRIVE - square wave to the Horizontal Vertical Deflection PCB, 50% duty cycle synchronized to the selected horizontal sync. This signal provides a sample of the horizontal sync to the horizontal amplifier on the Horizontal Vertical Deflection PCB.

HVPS_SYNC - synchronization pulse for High Voltage Power Supply, synchronized with the selected horizontal sync at the same, half, or one third the frequency.

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V_DRIVE - square wave negative going pulse to the Convergence Deflection PCB, synchronized to the selected vertical sync with the pulse width of about four horizontal periods.

Raster Timing Generator PCB - Operation

The Raster Timing Generator PCB generates a square wave that is phase-locked to the horizontal sync pulse. It generates timing signals such as Blanking that goes to the Video Processor PCB and Video Amplifier PCB, and the H_DRIVE signal that goes to the Horizontal Vertical Deflection PCB. The PLL (Phase Locked Loop) locks these signals to the horizontal sync signal. The Raster Timing Generator PCB has LEDs that indicate the type of sync pulse received and the status of the PLL circuit (see Figure 5-12).

The H_DRIVE signal supplies a sample of the horizontal scan frequency to the horizontal deflection amplifier on the Horizontal Vertical Deflection PCB for timing of the horizontal deflection waveform.

The Raster Timing Generator PCB checks the incoming syncs to make sure they are valid signals and within the frequency ranges (15 - 90 kHz - horizontal, and 45

- 120 Hz vertical). If the syncs are out of range, or there is no sync pulse, the Raster Timing Generator PCB generates an internal interlaced sync at 33.7 kHz horizontal and 60 Hz vertical.

The Raster Timing Generator PCB tells the System Controller PCB when there has been a source change using the SOURCE_VALID signal.

The Raster Timing Generator PCB generates the Blanking signal, and the horizontal Phase signal.

Blanking shuts off the image during times where there is no active video. The Blanking signal pulls the G1 voltage on the Video Amplifier PCB down far enough to make the CRT shut off. The Raster Timing Generator PCB receives the top, bottom, left, or right blanking command on the IIC bus and sends the appropriate Blanking signal to the Video Processor PCB. The Raster Timing Generator PCB receives the Blanking adjustment commands on the IIC bus.

The horizontal Phase signal adjusts the on-screen image horizontally to compensate for different phase requirements at different horizontal scan frequencies. The Raster Timing Generator PCB receives this command from the System Controller PCB on the IIC bus.

The Raster Timing Generator PCB sends several signals such as 280_CLOCK signal to the System Controller PCB to correctly set the timing for shading and convergence data.

In order to combat noise caused by crosstalk between supplies (beat patterns) the High Voltage Power Supply is phase locked to the incoming horizontal frequency by the HVPS_SYNC signal.

The horizontal flyback time gets shorter as the horizontal scan frequency increases. The Raster Timing Generator PCB works together with the Horizontal

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Vertical Deflection PCB to break the range of horizontal scan frequencies into four smaller ranges called bands (see Figure 5-12).

Figure 5-12

LEDs on the Raster Timing Generator PCB.

Raster Timing Generator PCB - Remove and Replace

Tools Needed

#1 Pozi-drive Phillips-head screwdriver

Parts Needed

Raster Timing Generator PCB - p/n 105238

To remove the Raster Timing Generator PCB:

Power OFF the projector by IR Remote or PC, and allow the cooling fans to run until they shut off automatically.

Turn the AC Circuit Breaker to the OFF position and unplug the AC Power Cord.

Disconnect all the external source video cables and control cables.

Remove the rear cover.

Remove the Back Panel. Remove the nine Pozi-drive Phillips-head retaining screws using the #1 Pozi-drive Phillips screwdriver.

Pull the black Card Extractor handles back to disconnect the Raster Timing Generator PCB connector and pull the PCB out of the Electronics Module.

Reverse the procedure to install the Raster Timing Generator PCB.

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5.6 Horizontal Vertical Deflection PCB

Horizontal Vertical Deflection PCB - Main Functions

Drive the main horizontal deflection coils to provide horizontal raster scan for the CRTs

Drive main vertical coils to provide vertical raster scan for the CRTs

Horizontal raster centering for all three colors

Switch mode power supply generating the required proportional DC supply

Horizontal width adjustment

Horizontal retrace switch network

Left/right pincushion and keystone correction

Vertical linearity adjustments individually for all three colors.

Vertical raster centering for all three colors

IIC interface.

Chapter 5---Electronics

Horizontal Vertical Deflection PCB - Inputs

H_BAND:0-3 - horizontal scan frequency bands, from Raster Timing Generator PCB.

/H_ENABLE - from the Raster Timing Generator PCB, enables the horizontal deflection supply. Low = enabled deflection, High = disabled deflection.

H_DRIVE - square wave from the Raster Timing Generator PCB, 50% duty cycle synchronized to the selected horizontal sync.

H_F2V - a DC voltage from the Raster Timing Generator PCB, proportional to horizontal frequency

H_LOCK (neg.) - Deflection Yoke Connector Interlock return from the Scan Reversal PCB.

DEFL_OK - deflection status signal from the Scan Reversal PCB (high = good, (about 2 V), low = no scan).

V_RAMP - vertical ramp waveform from the Convergence Deflection PCB, (about 4 Vpp).

V_PARAB - vertical parabola waveform from the Convergence Deflection PCB, (about 4 Vpp).

FRONT/REAR - front or rear projection status line from the Scan Reversal PCB. (FRONT = low, REAR = high).

FLOOR/CEILING - floor or ceiling projection status line from the Scan Reversal PCB. (FLOOR = low, CEILING = high).

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IIC_CLK - IIC clock line IIC_DATA - IIC data line IIC_SINT - IIC interrupt ±15 V - input power from the Low Voltage Power Supply, for the analog

circuitry. +5.1 V - input power from the Low Voltage Power Supply, for the digital

circuitry.

Figure 5-13

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Horizontal/Vertical I/O Diagram.

Chapter 5---Electronics

Figure 5-14

Horizontal/Vertical I/O Diagram for Scan Reversal and Video

Amplifier PCBs.

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Vertical Adjustment Pots

Figure 5-15

Physical layout of the Horizontal/Vertical PCB (note the Vertical Size

Adjustment Pots (Red-137, Grn-148, and Blu-160) on the lower right).

Horizontal Vertical Deflection PCB - Outputs

/SWEEP_OK - signal to the Video Amplifier PCB, derived from the H_ENA signal from the Raster Timing Generator PCB, and the DEFL_OK from the Scan Reversal PCB.

WIDTH_CTRL - a DC voltage to the Convergence Deflection PCB that adjusts the parabola waveforms used for geometric correction (about 4 V max.).

H_RGB(pos.) - horizontal deflection waveform return from the Scan Reversal PCB. A DC offset that shifts the reference for red, green, and blue image for centering.

H_OUT_FLYB - output waveform to the Scan Reversal PCB for the horizontal deflection coils on the CRTs.

H_LOCK (pos.) - +15 V to the Scan Reversal PCB for deflection yoke connector interlock.

V_RGB (pos.) - positive vertical deflection voltage to the Scan Reversal PCB. V_RGB (neg.) - negative vertical deflection voltage to Scan Reversal PCB. ±15 V - pass through voltage from Low Voltage Power Supply to Scan Reversal

PCB to power analog circuitry. +5.1 V - pass through voltage from Low Voltage Power Supply to Scan Reversal

PCB to power digital circuitry. H_CUR_FDBK - current feedback to horizontal waveform amplifier.

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Horizontal Vertical Deflection PCB - Operation

The Horizontal Vertical Deflection PCB consists of a RGB horizontal deflection amplifier and separate vertical deflection amplifiers.

The Horizontal Deflection Amplifier The horizontal deflection amplifier is a switching mode power supply that varies

according to the input horizontal sync frequency. The horizontal supply generates the sawtooth current-driven waveform that drives the horizontal deflection coils on the CRT. The sawtooth current waveform creates the raster on the CRT. The horizontal amplifier also generates the retrace waveform portion of the raster.

The horizontal deflection sawtooth waveform is modulated by other waveforms that perform geometric correction such as Pincushion, Keystone, Horizontal Centering, Horizontal Linearity and Horizontal Width adjustment. The Width Control voltage also goes to the Convergence Deflection PCB to adjust the geometric correction parabolas.

The H_F2V signal converts the input horizontal scan frequency to a voltage that switches from one band (see explanation of bands in the Raster Timing Generator PCB Operation section) to the next depending on the horizontal scan frequency. This adjusts the retrace time to correspond to the input horizontal frequency. The output of the horizontal supply is H_OUT_SUPPLY that goes on to the Scan Reversal PCB.

CRT Protection The Horizontal Vertical Deflection PCB uses the H_LOCK+, H_LOCK- and

DEFL_OK signal to protect the CRTs from being damaged if the deflection waveforms are lost. Refer to the CRT Protection section in Chapter 9 for a complete discussion of these and all the signals associated with CRT Protection.

The Horizontal Vertical Deflection PCB receives the DEFL_OK signal from the Scan Reversal PCB indicating the presence of the horizontal and vertical deflection waveforms. If there is a failure of any of the Deflection Yokes (horizontal or vertical), a current sense line on the Scan Reversal PCB forces DEFL_OK low. On the Horizontal Vertical Deflection PCB, the DEFL_OK signal becomes /SWEEP_OK and is sent to the Video Amplifier PCB where it shuts down G

. If DEFL_Ok is forced low, or if /H_ENA is forced high,

/SWEEP_OK goes high. The /SWEEP_OK goes to the Video Amplifier PCB. If it goes high, it shuts down the G

voltages and G2 Regulator circuit (see

Troubleshooting, CRT Protection section). Vertical Deflection Amplifier The vertical deflection sawtooth waveform is generated on the Convergence

Deflection PCB and timed to the vertical sync by the V_DRIVE signal from the Raster Timing Generator PCB. The Convergence Deflection PCB sends this waveform along with a parabola waveform V_PARAB to the vertical deflection amplifier on the Horizontal Vertical Deflection PCB. The Horizontal Vertical Deflection PCB takes V_RAMP, amplifies it and adds geometric correction with

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the V_PARAB waveform. The output waveform V_RGB+ goes to the Scan Reversal PCB and then drives the Vertical Deflection Yokes. The Vertical Deflection Yoke return signal to the Horizontal Vertical Deflection PCB is V_RGB-.

Horizontal Vertical Deflection PCB - Service Adjustments

Vertical Size Adjustment Tools Needed

Miniature Potentiometer-Trimmer Adjustment tool

To adjust the Vertical height (see Figure 5-15):

1. Remove the rear cover and pull the Interlock switch out to the Service

Mode position.

2. Power ON the projector by IR Remote or PC, and allow it to stabilize for a

minimum of 15 minutes

3. Use the X-hatch test pattern.

NOTE:

The green image is the reference to which the red image and blue image will be matched. The green height pot should not need adjustment except when the green CRT has been replaced.

4. Hide Blue and view Red and Green.

5. If Red is higher than Green at the top and lower than Green at the bottom

of the X-hatch image, or If lower than Green at the top and higher at the bottom, adjust Red vertical pot (R137) to correct the error.

Vertical Adjustment Potentiometers (see Figure 5-15)

Red - R137 Green - R148 Blue - R160

Figure 5-16

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Red image needs vertical adjustment (decrease).

Chapter 5---Electronics

Figure 5-17

Red image needs vertical adjustment (increase).

If Red is higher than Green at the top and bottom, or lower than Green at the top and bottom, the Red image may not being centered correctly. This can be corrected with the centering adjustment (see Model 250 User’s Guide, Chapter 5).

Figure 5-18

Red image needs vertical centering.

If the Red height pot does not completely eliminate the difference in height between Red and Green, balance the difference at the top and bottom. Too much of an difference at the top or bottom makes convergence procedures harder to accomplish.

4. Repeat Steps 2 and 3 above for Blue while hiding Red.

5. Recheck all Geometry and Convergence settings (see User’s Guide) and

readjust wherever necessary.

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Horizontal Vertical Deflection PCB - Remove and Replace

The Horizontal/Vertical (H/V) Deflection PCB is located in the upper portion of the Electronic Module card cage.

Tools Needed:

#1 Pozi-drive Phillips-head screwdriver

Parts Needed:

Horizontal Vertical Deflection PCB p/n 105236

To remove the Horizontal/Vertical (H/V) Deflection PCB:

1. Power off the projector by IR Remote or PC, and allow the cooling fans to

run until they shut off automatically.

2. Turn the AC Circuit Breaker to the OFF position and unplug the AC

Power Cord.

3. Remove the rear cover.

4. Disconnect six connectors; J34, J35, J36, J41, J42, and J43 (see Figure

5-15). Move the cables out of the way.

5. Loosen (it is not necessary to remove) the 5 Pozi-drive Phillips-head

screws that secure the Horizontal Vertical Deflection PCB to the electronic module cage.

6. Remove the Horizontal Vertical Deflection PCB by sliding it toward the

left side of the projector (this is the upward direction if the electronic module is tilted up) so that the mounting screws clear the access holes. Then lift the side of the PCB that is nearest the front of the projector first and angle it upward so that the side closest to the rear clears the lip of the electronic module frame. Be careful when removing or reinstalling the PCB to avoid damaging it on the fan screws or cable clamps.

7. Reinstall the Horizontal Vertical Deflection PCB by lowering the side that

is nearest to the rear of the projector in first until it clears the electronic module edge, then lowering the other side. Carefully fit the board over the mounting screws and slide the board into position. Tighten the screws and reconnect the connectors.

5.7 Convergence Deflection PCB

Convergence Deflection PCB - Main Functions

Generation of various waveforms for the horizontal and vertical deflection.

Height control

Generation of waveforms for dynamic focus

Various geometry correction functions for the horizontal and vertical axes

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Convergence output amplifiers for all colors and both horizontal and vertical axes

Convergence enable and raster fill function

ILA® assembly driver circuitry with temperature compensation

Phase locked loop for ILA® assembly drivers

IIC serial bus interface

Convergence Deflection PCB - Inputs

X_RGB_CONV - x-axis Convergence waveform from the System Controller PCB (the amplitude for full-scale correction is about 1 Vpp).

Y_RGB_CONV - y-axis Convergence waveform from the System Controller PCB (the amplitude for full-scale correction is about 1 Vpp).

CORR_SYNC - square wave from the System Controller PCB, logic level synchronization signal for the horizontal axis.

V_DRIVE - square wave from the Raster Timing Generator PCB, logic level synchronized to vertical sync with four horizontal line duty cycle.

WIDTH_CONTROL - a DC waveform from the Horizontal Vertical Deflection PCB that controls the image width.

IIC_CLK - IIC clock line. IIC_DATA - IIC data line. IIC_SINT - IIC interrupt line. ±15 V - input power from the Low Voltage Power Supply for the analog circuitry. +5.1 V- input power from the Low Voltage Power Supply for the digital circuitry.

Convergence Deflection PCB - Outputs

RGB_ILA®(pos) - positive outputs to the ILA® for the red, green, and blue ILA

driver circuitry (about ±12 Vpp). RGB_ILA®(neg) - negative outputs to the ILA® for the red, green, and blue ILA

driver circuitry (about ±12 Vpp). H_PARABOLA - horizontal parabola for dynamic focus section of the High

Voltage Power Supply. V_PARABOLA - vertical parabola for dynamic focus section of the High Voltage

Power Supply. V_RAMP - vertical ramp waveform to the Horizontal Vertical Deflection PCB

(about 4 Vpp). V_PARABOLA - vertical parabola waveform to the Horizontal Vertical

Deflection PCB (about 4 Vpp).

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Figure 5-19

5-30 Model 250 Service Manual

Convergence Deflection PCB I/O Diagram.

Chapter 5---Electronics

Figure 5-20

Model 250 Service Manual 5-31

Convergence Deflection PCB I/O Diagram.

Chapter 5---Electronics

Figure 5-21

Physical layout of the Convergence/Deflection PCB.

Convergence Deflection PCB - Operation

The Convergence Deflection PCB performs four main functions. It generates the vertical deflection sawtooth waveform. It generates the square waves that bias the three ILA®s. It controls the amplitude of waveforms used for convergence corrections, and it generates the parabolic waveform used for dynamic focus.

The Convergence Deflection PCB receives the V_DRIVE signal, which is a sample of the vertical sync, from the Raster Timing Generator PCB. The Convergence Deflection PCB has a Waveform Generator Section that generates the vertical deflection sawtooth waveform and outputs the V_RAMP signal that drives the vertical amplifier on the Horizontal Vertical Deflection PCB. The vertical amplifier drives the CRT deflection coils for vertical deflection. The Waveform Generator also generates the parabolic waveforms used for geometry correction such as bow, pincushion, keystone, and linearity

Each of the ILA®s is biased by a square wave generated by the Waveform Generator on the Convergence Deflection PCB. Each ILA® is biased separately

through the ILA

Bias command in the Factory Adj. Menu. The commands are

received through the IIC interface. As the square wave that drives the ILA® is increased, the ILA® becomes more sensitive to the image light that strikes the photoconductive layer and outputs more light. The command that controls the frequency of the ILA global command for all the ILA

Attached to the green ILA

the ILA ILA

. It sends the Convergence Deflection PCB a signal that adjusts the green

bias to compensate for temperature variations inside the projector. If the

bias square wave is referred to as ILA® Sensitivity. It is a

s and is received from the IIC interface.

mount is a thermistor that senses the temperature of

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temperature of the green ILA® increases, the bias is increased to maintain a constant ILA® output.

The Convergence Deflection PCB receives commands for x and y-axis convergence from the System Controller PCB. The Convergence Deflection PCB has a Convergence Control Section that receives the convergence commands, waveforms from the Waveform generator, and geometric correction data from the IIC interface. It amplifies the convergence data and outputs it to the Scan Reversal PCB.

The Waveform Generator section generates a horizontal and vertical parabolic waveforms that the High Voltage Power Supply uses for dynamic focus.

Convergence Deflection PCB - Remove and Replace

The Convergence/Deflection PCB is located on the bottom side of the Electronic Module card cage (see Figure 5-2).

Tools Needed

#0 Pozi-drive Phillips-head screwdriver

Parts Needed

Convergence Deflection PCB p/n 105210

To remove the Convergence/Deflection PCB:

1. Power off the projector by IR Remote or PC, and allow the cooling fans to

run until they shut off automatically.

2. Turn the AC Circuit Breaker to the OFF position and unplug the AC

Power Cord.

3. Remove the rear cover.

4. Tilt the Electronic Module up.

5. Disconnect six connectors; J31, J32, J33, J38, J39, and J40 from the

Convergence/Deflection PCB (see Figure 5-21). Move the cables out of the way.

6. Loosen (it is not necessary to remove) the five Pozi-drive Phillips-head

screws that secure the Convergence Deflection PCB to the Electronics Module card cage.

7. Remove the Convergence Deflection PCB by sliding it upward so the

mounting screws will clear the access holes, then angle the right side outward. In order to get the right side of the PCB out, it may be necessary to first, move the PCB out enough to clear the access holes. Then, angle the left side out just enough for the top 2 fins of the heat sync to fit over the Electronics Module frame lip. This will allow a little more clearance for the right side to be removed. Then, maneuver the right side of the PCB out.

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8. Reinstall the Convergence/Deflection PCB by lowering the right side in

first until it clears the electronic module edge, then lowering the left side in.

NOTE:

It may be necessary to fit the top 2 fins of the heat sync over the electronic module frame lip at the left to get enough clearance for the right side to be installed. Carefully fit the board over the mounting screws and slide the PCB into position. Tighten the screws and reconnect the connectors.

5.8 Scan Reversal PCB

Scan Reversal PCB - Main Functions

Reverses of scan in both horizontal and vertical axes

Outputs deflection waveform to the Deflection Yokes on the CRTs

Outputs convergence data to Convergence Yokes on the CRT

Horizontal width adjustment for each color (R, G &B)

Scan failure detection for (horizontal and vertical) deflection amplifiers

Scan Reversal PCB - Inputs

H_OUT_FLYBACK - output horizontal deflection waveform from the Horizontal Vertical Deflection PCB (about 800 Vpp).

H_LOCK (pos.) - horizontal interlock for the yoke connectors from the Horizontal Vertical Deflection PCB (about 5 V when closed, 15 V when open).

H_RGB (pos.) - return of horizontal deflection waveform to the Horizontal Vertical Deflection PCB.

V_RGB (pos.) - output signals of red, green, and blue from the Vertical Amplifier of the Horizontal Vertical Deflection PCB (about 40 Vpp).

X_RGB (pos.) - output signals of the red, green, and blue from the Horizontal Convergence Amplifier for the X-axis from the Convergence Deflection PCB.

Y_RGB (pos.) - output signals of the red, green, and blue from the Horizontal Convergence Amplifier for the Y-axis from the Convergence Deflection PCB.

±15 V - input power from the Horizontal Vertical Deflection PCB for the analog circuitry.

+5.1 V - input power from the Horizontal Vertical Deflection PCB for the digital circuitry.

From Yokes H_RGB_YOKE (neg.) - bottom of red, green, and blue horizontal deflection

yokes. V_RGB_YOKE (neg.) - bottom of red, green, and blue vertical deflection yokes. X_RGB_YOKE (neg.) - bottom of red, green, and blue x-axis convergence yokes.

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Y_RGB_YOKE (neg.) - bottom of red, green, and blue y-axis convergence yokes. RGB_LOCK (neg.) - interlock for red, green, and blue deflection yokes (5 V

when closed or 0 V when open).

Scan Reversal PCB - Outputs

H_LOCK (neg.) - Horizontal Interlock for the yoke connectors to the Horizontal Vertical Deflection PCB (about 5 V when closed, 15 V when open).

FRONT/REAR - front or rear projection status line to Horizontal Vertical Deflection PCB (front = low, rear = high).

FLOOR/CEIL - floor or ceiling status line to the Horizontal Vertical Deflection PCB (floor = low, ceiling = high).

DEFL_OK - deflection status line from the Horizontal Vertical Deflection PCB (high (about 2 V) = good, low = no scan).

X_RGB(neg) - current feedback signals of the red, green, and blue Horizontal Convergence Amplifier for the x-axis to the Convergence Deflection PCB.

Y_RGB (neg.) - current feedback signals of the red, green, and blue Horizontal Convergence Amplifier for the y-axis to the Convergence Deflection PCB.

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

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Figure 5-22

Scan Reversal PCB I/O Diagram.

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Figure 5-23

Model 250 Service Manual 5-37

Scan Reversal PCB I/O Diagram for Horizontal Vertical Deflection PCB.

Chapter 5---Electronics

Figure 5-24

Scan Reversal PCB I/O Diagram for CRT Yokes.

Scan Reversal PCB - Operation

The Scan Reversal PCB has several functions. It provides an interface for scan reversal, and provides for horizontal width adjustment. The Scan Reversal PCB outputs the convergence and deflection waveforms that drive the CRT convergence and deflection yokes, and it contributes significantly to the CRT Protection circuit.

The Scan Reversal PCB provides an interface for reversing the projection mode from front to rear projection and from upright to inverted (upside down) mounting projection setups. The projection modes are changed by switching a jumper from one connector to another on the Scan Reversal PCB. J100 and J101 are for horizontal scan connections. J53 and J53A are the vertical scan connections, and J50 and J50A are convergence jumper connections. The Model 250 comes set for

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front/upright projection. This means the horizontal scan jumper is plugged into J100, the vertical scan jumper is plugged into J53, and the convergence jumper is plugged into J50.

NOTE:

Whenever the horizontal scan jumper is switched from front projection to

rear projection, the convergence must also be switched from J50 to J50A. The Scan Reversal PCB sends two signals (FRONT/REAR and

FLOOR/CEILING) back to the Horizontal Vertical Deflection PCB, which sends the signals back to the System Controller PCB through the IIC data bus. This allows the System Controller PCB to properly output convergence and shading data, however the shading, convergence, geometry will need to be adjusted after switching deflection modes.

The Scan Reversal PCB receives the deflection waveforms from the Horizontal Vertical Deflection PCB. The horizontal deflection waveforms go through the horizontal size adjustment inductors (L1, L2, and L3) and is output to the Deflection Yokes on the CRT without any further signal processing. The vertical deflection waveforms pass through the Scan Reversal PCB without any further signal processing. The convergence data passes through the Scan Reversal PCB to the Convergence Yokes on the CRT without any further signal processing.

The Scan Reversal PCB provides for the adjustment of horizontal scan width. Inductor L1 adjusts the red horizontal width, and L5 adjusts the blue horizontal width. L3 increases the horizontal size range of red and blue.

The Scan Reversal PCB contains two major components of the CRT Protection circuit. The first component is the DEFL_OK signal that goes back to the Horizontal Vertical Deflection PCB. The Scan Reversal PCB has a sensing inductor (coil) that detects the presence of a horizontal and vertical deflection waveform for each CRT. These sense lines combine to drive the DEFL_OK signal. If any of the deflection waveforms are not present, the DEFL_OK signal goes low. As the /SWEEP_OK signal it shuts down the G1 and G2 regulator voltages on the Video Amplifier PCB. It also shuts down the high voltage section of the High Voltage Power Supply (see CRT Protection section of Ch. 7-- Troubleshooting).

The other component of the CRT Protection circuit on the Scan Reversal PCB is the H_LOCK+ and H-LOCK- signals. These signals are actually one voltage (+15 V) that forms a series circuit through each vertical and horizontal deflection yoke connector on each CRT. If any of the deflection yokes are not properly or securely installed, the H_LOCK- signal shuts down the horizontal amplifier on the Horizontal Vertical Deflection PCB (see CRT Protection section of Ch. 7-- Troubleshooting).

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Scan Reversal PCB - Service Adjustments

Figure 5-25

Physical layout of the Scan Reversal PCB.

Horizontal Size adjustment The Horizontal size adjustment must be performed after the Horizontal Vertical

Deflection PCB is replaced. Tools Needed

Delrin .100 hex alignment tool Equipment Needed No equipment needed To adjust the horizontal size coils (see Figure 5-25):

4. Remove the rear cover and pull the Interlock switch out to the Service

Mode position.

5. Power ON the projector by IR Remote or PC, and allow it to stabilize for a

minimum of 15 minutes

6. Use the X-hatch test pattern.

7. Hide Blue. View Red and Green.

8. If the Red image is outside the Green image on both sides, or inside the

Green image on both sides, use a Delrin .100 hex alignment tool to adjust the Red horizontal size coil to correct the error. If the Red image is outside the Green image on one side and inside of Green on the other side, this is most likely caused by Red not being centered correctly and can be corrected with the centering adjustment (User’s Guide, Chapter 5). If the Red horizontal size coil does not completely eliminate the size error between Red and Green, balance the difference on both sides to allow for easier convergence.

9. Repeat Steps 4 and 5 above for Blue while hiding Red.

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10. Recheck all Geometry and Convergence settings and readjust wherever

necessary.

11. Replace the rear cover.

Front/Rear Projection Jumper Settings In the procedures below each of the jumpers mentioned have a specific purpose:

J100 and J101 are the horizontal scanning jumpers, J 53 and J53A are the vertical scanning jumpers, and J50 and J50A are the convergence jumpers.

CAUTION

Do not attempt to switch jumpers while the

projector is operating. The projector must be powered OFF when Scan Reversal Jumpers are being changed.

Front/Rear Jumper Setting (Horizontal Reverse)

The Horizontal Scan Reversal Jumper reverses the image projection for front or rear projection. Figure 5-25 illustrates the jumpers’ location on the Scan Reversal Board.

The Model 250 Projector is shipped with the jumper plugs inserted in J50 and J100 for front/upright projection (see Table 5-1 for other orientations).

To set the Horizontal Scan Jumper:

1. Power off the projector by IR Remote or PC, and allow the cooling fans to

run until they shut off automatically).

2. Turn the AC Circuit Breaker to the OFF position and unplug the AC

Power Cord.

3. Remove the rear cover.

4. Verify that the Horizontal Scan Reversal jumper is plugged into J100 and

the convergence jumper is plugged into J50 for front projection (see Figure 5-25 and Table 5-1).

5. Switch the Horizontal Scan Reversal jumper to J101 and the Convergence

Jumper to JA50 for rear projection (see Figure 5-25 and Table 5-1).

6. Replace the projector cover.

7. Power ON the projector and allow it to stabilize for a minimum of 15

minutes. It is recommended that the projector be operating for a least one hour before performing shading adjustments.

8. Recheck centering, convergence, and shading when changing jumpers for

front or rear screen projection.

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Chapter 5---Electronics

Table 5-1

Orientation

Front/Floor

Projection orientation jumper settings.

Convergence.

P50 goes to:

Vertical.

P53 goes to:

J50 J53 J100

Horizontal.

P100 goes to:

(Upright) Front/Inverted*

Rear/Floor

JA50 JA53 J101 JA50 J53 J101

(Upright) Rear/Inverted*

CAUTION!

see

NOTE:

Whenever the horizontal scan jumper is switched from front projection to

below

J50 JA53 J100

rear projection, the convergence must also be switched from J50 to J50A. Floor/Ceiling Jumper Setting The Ceiling/Floor jumpers invert the image vertically for use in some situations

that use dual mirror projection setups.

CAUTION!

mounted in the inverted (upside down) position,

The Model 250 Projector can not be

however there are dual mirror applications where the vertical scan jumper will need to be changed to the inverted setting (JA53).

Figure 5-21 illustrates the location of the jumpers on the Scan Reversal Board. The Model 250 Projector is shipped in the normal vertical projection position with the jumper plug inserted into J53. For an inverted vertical setup this jumper plug must be inserted into JA53. (see Table 5-1 for other orientations).

To invert the vertical image:

1. Power off the projector by IR Remote or PC, and allow the cooling fans to

run until they shut off automatically.

2. Turn the AC Circuit Breaker to the OFF position and unplug the AC

Power Cord.

3. Remove the rear cover.

4. Verify that the Vertical Scan Jumper is plugged into J53 for upright

projection. (see Figure 5-25 and Table 5-1).

5. Switch the Vertical Scan Jumper to JA53 for inverted projection. The

Convergence Jumper will not need to be changed for inverted projection unless the Horizontal Scan Jumper is being changed.

6. Replace the rear cover.

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Chapter 5---Electronics

7. Power ON the projector and allow it to stabilize for a minimum of 15

minutes. It is recommended that the projector be operating for a least one hour before performing shading adjustments.

8. When changing jumpers for floor or ceiling screen projection, Centering,

Convergence and Shading must be rechecked.

Scan Reversal PCB - Remove and Replace

The Scan Reversal PCB is located on the front side of the Electronic Module (see Figure 5-2).

Tools Needed

#1 Pozi-drive Phillips-head screwdriver

Parts Needed

Scan Reversal PCB p/n 102585

To remove the Scan Reversal PCB:

1. Power off the projector by IR Remote or PC, and allow the cooling fans to

run until they shut off automatically.

2. Turn the AC Circuit Breaker to the OFF position and unplug the AC

Power Cord.

3. Remove the projector rear cover.

4. Disconnect seven connectors (seeFigure 5-25): J52, J54, J64, J65, J66, J50

(or J50A), and J100 (or J101). To remove, push in slightly, squeeze the tabs, and then pull connector out.

5. Move all cables out of the way.

6. Remove the four Pozi-drive screws (see Figure 5-25) and lift the board off

the Electronics Module.

7. Reinstall in the reverse order from above.

5.9 Video Amplifier PCB

Video Amplifier PCB - Main Functions

Amplification of video signals and driving the cathode of all three CRTs

Sensing the cathode beam current for all three CRTs

G1 regulator for all three CRTs

Blanking drive section

Phosphor protection for all three CRTs

G2 regulator and adjustment of black level (screen) for all CRTs

DC restoration for the video signals

CRT interface for focus, heater voltage and ARC ground

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Chapter 5---Electronics

Video Amplifier PCB - Inputs

RGB_VIDEO - image pre-amp signals from the Video Processor PCB (about 0.5 Vpp).

RESTORE - image DC restorations pulse from Video Processor PCB, logic level positive going 4% duty cycle.

BLANKING - Blanking signal, logic F type. G1_SUPPLY - supply for G1 grid on CRTs from High Voltage Power Supply

(about -150 V). G1_BIAS - brightness control line from Video Processor PCB (0-5 VDC). RGB_G2 - G2 (black level) control lines from Video Processor PCB (0-3.1 V). G2_SUPPLY - supply for G2 grid on CRTs from High Voltage Power Supply

(about 1200 V). RGB_ FOCUS - Focus supply for CRTs from the High Voltage Power Supply

(approximately 7 kV). SWEEP_OK - deflection status line from the Horizontal Vertical Deflection PCB. +80 V - from the Low Voltage Power Supply ±15 V - input power for the analog circuitry from the Low Voltage Power Supply.

6.2 V - input power for the CRT filaments heaters from the Low Voltage Power Supply.

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Chapter 5---Electronics

Figure 5-26

Video Amplifier PCB I/O Diagram

Model 250 Service Manual 5-45

JVC 250 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual