Hughes JVC Projector 230 Sc Service Manual

Chapter 1---Introduction
Model 230 Service Manual1-3
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
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...

Chapter 1---Introduction
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Model 230 Service Manual 

Chapter 2---System Description
Model 230 Service Manual2-1
2.0   System Description
Contents
2.1   Introduction ..............................................................................................2-1
2.2   Optical System .........................................................................................2-2
2.2.1   Image Path ...................................................................................2-2
2.2.2   Arc Lamp Light Path...

Chapter 2---System Description
2-2Model 230 Service Manual
cabling. It also contains the Backplane board which is used to electrically
interconnect the printed circuit boards, power supplies and other units in the
projector, and the Video Input Cards that interface with different kinds of
input signals.
•  The CRT Section is located beneath the electronics card cage and contains
the 3 CRTs, 3 Relay Lenses, 3 ILA®s and the Video Amplifier Board.
2.2   Optical System
Introduction: The Model 230 Optics...

Chapter 2---System Description
Model 230 Service Manual2-3
(changing its polarization) by the signal on the input side of the ILA® assembly.
The light is then reflected back from the output side of the ILA® assembly, then
travels through the prism to be picked up by the projection lens.
NOTE: The prism reflects horizontally polarized light and passes vertically
polarized light. Light from the arc lamp is polarized horizontally and reflects from
the prism into the ILA® assembly then back out again, after...

Chapter 2---System Description
2-4Model 230 Service Manual
directly at or touch the Xenon Arc Lamp. Service should be performed by
Hughes-JVC certified technicians only.
Xenon Arc Lamp/Condensing Lens: High pressure, ionized xenon gas
supports a high-current electrical arc to produce the intense, white light used in
the Model 230 projector.
First Condensing Lens: The high intensity light output from the Xenon Arc
Lamp goes through the First Condensing Lens (attached to the rear of the Arc
Lamp housing)...

Chapter 2---System Description
Model 230 Service Manual2-5
Figure 2-1.  Optical System Block Diagram 

Chapter 2---System Description
2-6Model 230 Service Manual
2.3   Electronics System
2.3.1 General Description
The Model 230 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...

Chapter 2---System Description
Model 230 Service Manual2-7
2.3.2   Power Supplies
The Model 230 includes three power supply assemblies.
•  Low Voltage Power Supply
•  Arc Lamp Power Supply
•  High Voltage Power Supply
Low Voltage Power Supply (LVPS)
P75P76
1
3
51-7
8
9
10
11
12
13
14
15
16
17
18To P8 on
Backplane AC
INPUTLine
Earth
NeutralLV Ret
/LV_ENA
/LV_OK
+24v Fans
+5.1v STBY
+5.1v
+6.2v
+15V
-15v
+80V
/COVER_ON
/FAN_ENA
Figure 2-3.   LVPS Input/Output Diagram
Main Functions:
•  Provide all the low...

Chapter 2---System Description
2-8Model 230 Service Manual
/LV_OK: When /LV-ENA is enabled, this diagnostic signal indicates to the
System Controller the status of the non-standby supply (all outputs working or
not working).
Operation:
The main power is filtered via the input filter to prevent radiation from escaping
back to the power line. From the line filter, AC power is fed into the Low Voltage
Power Supply module where AC is rectified, filtered, and compensated for power
factor correction.
The +5.1V...