Hughes JVC Projector 250 Sc Service Manual

							SERVICE
MANUAL
Model 250 Projector
Phone: (760) 929-5300
Fax: (760) 929-5410
2310 Camino Vida Roble
Carlsbad, California 92009 
						

							iiModel 250 Service Manual
DECLARATION OF CONFORMITY
PER ISO/IEC GUIDE 22 AND EN 45014
Manufacturer
:
Hughes JVC
2310 Camino Vida Roble
Carlsbad, Ca 92009
USA
Hughes-JVC declares that this product conforms to the following Product
Specifications (Directive/Standard):
Safety: EN 60950
IEC 950 (1992)
EMC: EN 55022 (1988) / CISPR-22 (1986) Class A
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
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
© 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 Projector Service Manual iii
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 
						

							ivModel 250 Service Manual
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 
						

							Chapter 1---Introduction
Model 250 Service Manual 1-1
1.0 Introductio n
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.
The User’s Guide covers
! Installation,
! Operation,
! Setup Adjustments
! Specifications
This Service Manual covers:
! Projector functional description
! Service adjustments
! Removal and replacement of subassemblies
! Troubleshooting
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. 
						

							Chapter 1---Introduction
1-2 Model 250 Service Manual
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
®Image Light Amplifier
I/O Input/Output
I/R Infrared
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 Phase 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 
						

							Chapter 1---Introduction
Model 250 Service Manual 1-3
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 
						

							Chapter 2---System Description
Model 250 Service Manual 2-1
2.0  System De s cription
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
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
2-2 Model 250 Service Manual
Figure 2-1  
Overview of the Model 250 projector showing major components
2.2 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 over-
voltage 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. 
						

							Chapter 2---System Description
Model 250 Service Manual 2-3
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, cold mirrors get very hot
.
! Light Pipe - The Light Pipe acts as an Integrator to spread out the beam of
light creating a uniform distribution of light across the face of the ILA®.
This will result in a more uniform image on the screen