Hughes Jvc 200 Projector Service Manual

							Chapter 3 Service Adjustments 
3.   Use the right/left arrow keys on the remote control and adjust 
the Flat Field to 0%. 
4.   From the System menu, select Maintenance, then select #3, 
ILA® Bias.  Record the ILA® Bias current value (the Green bias 
will be readable). This bias value will be returned to when this 
procedure is complete. The Green value only need be recorded 
because Red and Blue returns to their original values when 
Green is reset. 
5. Use the right arrow key to increase the ILA® Bias so the Flat 
Field turns white. If the screen begins to turn from white to a 
yellow-tinge, use the left arrow and adjust the bias back until an 
all white flat field is observed.  The flat field screen must be 
white to properly perform the arc lamp focus and alignment. 
6. Loosen the large flathead screw (½ turn CCW) at the bottom of 
the Arc Lamp cover (Figure 4-2), and lift the cover. 
7. Defocus the Arc Lamp by turning the Focus Adjust Screw (see 
Figure 3-1) until a bright, circular area (see Figure 3-2) is 
achieved. This is the Arc Lamp’s “hot spot.” The sides, top, an\
d 
bottom areas will taper off in brightness. When performing 
defocus, do not attempt to narrow the circle too much-try to 
obtain a uniform circular area. 
 
Figure 3-1. Arc Lamp Focus adjustments. 
8. Loosen the 4 X-axis (horizontal) alignment screws (indicated by 
the letter H inside the screw heads in Figure 3-1). 
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Figure 3-2.   Arc Lamp “Hot Spot” (whitest area) is off-center vertically 
 and horizontally. Adjust to center the “hot spot”. 
9. Insert a flathead screwdriver into one of the horizontal 
alignment slots shown in Figure 3-1 and pry back and forth to 
slide the plate. Center the “hot spot” horizontally. 
10. Tighten the 4 horizontal alignment screws. 
11. Loosen the 2 vertical alignment screws indicated by the letter V 
inside the screw heads in Figure 3-1. 
12. Use a flathead screwdriver in the vertical alignment slots, 
shown in Figure 3-1, to pry the vertical plate up or down so that 
the “hot spot” is centered vertically. 
13. Tighten the 2 vertical alignment screws. 
14. Adjust the focus screw for overall brightness from the center to 
the edges with a minimum of rolloff. NOTE: Rolloff is the 
gradual difference in brightness from the center of the screen 
to the edges. Ensure the bright area extends to the edges of 
the screen but not over the edges. If possible, use a light 
meter to perform this step. If using a light meter, try to achieve 
a rolloff of no more than 4:1 to the screen corners. The darker 
areas in each of the corners should be balanced evenly. 
15. When the Arc Lamp is focused over the entire screen area and 
balanced vertically and horizontally, reset the Green ILA® bias 
to original value. 
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3.2 Arc Lamp Current Setting 
The Arc Lamp current must be set whenever an Arc Lamp or Arc 
Lamp Power Supply is replaced. Routinely recheck current about 
every 500 hours of operation. This procedure is performed using 
two DVMs, for convenience, but can be performed with one DVM 
by moving the leads back and forth between the two test points 
mentioned and changing the scale ranges on the DVM. 
To perform the Arc Lamp Current Setting: 
1. Verify that power is off to the projector, or turn power off with 
the remote (it is not necessary for the circuit breaker to be off).  
2. Place a DVM (set to read up to 200VDC) across the Arc Lamp 
DC INPUT ± terminals, J74, (Figure 3-3). 
3. Turn projector power on. 
Figure 3-3.   Arc Lamp Power Supply connections. 
4. Place another DVM, set to read at least 200 millivolts dc, 
across the test points inside the small rectangular aperture, 
near the upper left of the Arc Lamp Power Supply cover (see 
Figure 3-4). NOTE: This test point reads millivolts across a 
shunt that has been selected so that a 1 millivolt reading on the 
DVM is equal to 1 amp of Arc Lamp current.  
 
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Adjust the Arc 
Lamp current 
with this pot. 
Place the 
second DVM, 
from Step 3, 
across these 
terminals. 
Figure 3-4.  Arc Lamp Power Supply aperture. 
5. Multiply the results from Step 2 and Step 3 together (Bear in 
mind that the millivolt reading from Step 3 should be interpreted 
as amps, i.e. 1millivolt=1 amp). 
6. The resulting power from Step 4 should equal 750 watts.  
7. If the result is not 750 watts, adjust the trimmer pot (refer to 
Figure 3-4). CW=increase, CCW=decrease. If increasing, 
notice that the Arc Lamp voltage from Step 2 may decrease 
slightly. Adjust the trimmer pot until power is 750 watts. 
CAUTION! Do not adjust beyond 775 watts or damage to the 
equipment may occur. 
3.3 Electronic Module Tilt-up 
1. Remove the rear cover (Section 4.2). 
2. Release the clasp on the left side of the electronic module (turn 
CCW and pull out). 
3. Pull out the release pin on the rear-right side of the electronic 
module to tilt it up. Tilt the electronic module up to a vertical 
position. 
4. Ensure the holding pin locks the electronic module in place. 
3.4 ILA® Back Focus 
The ILA® Back Focus adjustment moves the ILA®/Relay Lens/CRT 
assemblies together to adjust the focal length. This adjustment 
allows the zoom lens’ tracking to remain focused throughout the 
entire range. Use Focus test pattern to perform this adjustment for 
each color. This procedure performs the Green ILA® Back Focus. 
For best results, perform ILA® Back Focus with 2 people.  One 
person will watch the screen close-up and the other will move the 
ILA®/Relay Lens/CRT assemblies back and forth. The adjustment 
is factory-set but may need some touch-up in the field. 
To adjust the ILA® Back Focus: 
1. Remove the rear cover (Section 4.2). 
2. Tilt the Electronic Module up (Section 3.3). 
3. For this procedure, view Green. Hide Red and Blue. 
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							Chapter 3 Service Adjustments 
4. Select the Focus test pattern. 
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). NOTE: Skip this step when 
using an optional fixed lens. 
7. Use left and right arrow keys to focus the projection lens to get 
sharply focused spacer balls.  NOTE 1: Spacer balls are used 
inside the ILA® Assembly to separate the layers. They are tiny, 
random, irregularly-shaped spots that are visible throughout the 
image.  Look directly in front of the screen in the lighter areas of 
the image to view. From throw distances shorter than 4 meters, 
spacer balls are difficult to see.  
8. Zoom the lens to a wide angle position (largest image). NOTE: 
Skip this step when using an optional fixed lens. 
9. 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 (Figure 3-5).  Move the CRT snug against the 
collar to get additional range, and then, retighten the collar. 
10. Loosen the 2 hex bolts (Figure 4-12) on the ILA® assembly in 
front of the Relay Lens. 
11. Slide the Relay Lens/CRT/ILA® assembly forward or backward 
until the sharpest spacer ball focus is achieved. 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 6-11 above for any other assembly needing ILA® 
Back Focusing. Be sure to hide the other 2 colors. 
 
NOTE: The CRT Mechanical Focus procedure (Section 3.5) is often 
performed sequentially with the CRT Rotation procedure (Section 3.6). The 
same two set screws (Figure 3-5) are loosened when doing either of these 
procedures. When performing the procedures in sequence, ensure the two s\
et 
screws are secure when either the focus lock screw or the CRT thumbscrew is 
tightened after finishing each adjustment. Do not leave the set screws loose 
when securing either the focus lock screw or the CRT thumbscrew. Turning 
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either one of these adjustments while the set screws are loose may 
cause the CRT to go out of focus or rotate. 
3.5 CRT Mechanical Focus 
The CRT Mechanical focus is factory-set and will not normally 
require adjustment. When a CRT is replaced, the CRT mechanical 
focus must be reset. Adjust colors individually.  After completing, 
recheck other colors for additional adjustment.  Replacing the CRT 
could cause other colors to become misadjusted.  Use the Focus 
test pattern (an external signal or other test patterns can also be 
used) for adjustment. 
To adjust the CRT Mechanical Focus: 
1. Remove the rear cover (Section 4.2) 
2. Tilt the Electronic Module to the upright position (Section 3.3). 
3. Select the Focus test pattern. 
3. Zoom the Projection Lens to the widest angle (largest image) 
and adjust the Projection Lens focus for the sharpest image of 
the Focus test pattern. 
4. Tilt the Electronic Module up (Section 3.3). 
5. Loosen the two set screws (Figure 3-5) near the top of the CRT 
sleeve. 
6. Loosen the CRT focus lock screw located on the Guide Plate at 
the top of the CRT shield (Figure 3-5). The CRT is now free to 
slide. 
7. Grasp the CRT thumbscrew (Figure 3-5) and slide the CRT 
back and forth until the image is focused as sharply as possible 
(be careful not to loosen the CRT thumbscrew which could 
cause the CRT to rotate). 
8. Tighten the set screws first, then the CRT focus lock screw. 
NOTE: Tighten set screws before focus lock screw. The focus 
lock screw can slightly defocus or rotate the CRT as it is being 
tightened if the set screws are loose. 
9. Repeat the above steps for the Red and Blue CRTs. 
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CRT Holder 
Ring 
Focus Lock 
ScrewSet Screw 
Set Screw 
CRT Thumb 
Screw 
Guide Plate 
CRT Shield 
Figure 3-5.   CRT Mechanical Focus adjustments. 
3.6 CRT Rotation 
The CRT tilt adjustment aligns the CRT level with the screen. This 
is a factory-set adjustment and should not need adjusting unless 
the CRT or yoke is moved. 
Remove the rear cover (Section 4.2) and tilt the electronic module 
up (Sections 3.3).  
1. Select Test Pattern 8, Center/Lin. 
2. View the color for the CRT that requires rotation. Hide the other 
2 colors. 
3. In the Geometry menu, set “Reg Enable” to off by unchecking 
the box. Unchecking the Reg Enable box temporarily disables 
any convergence corrections that have been performed with a 
different CRT/Yoke assembly and sets these values to the 
default levels so that CRT Rotation can be accomplished 
correctly. 
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4. In the Geometry menu, access Bow, Skew, Pincushion, and 
Keystone. Note the values for each setting.  After recording 
values, set each to the default level of 128 (For Skew, select 
the color of the CRT that is to be rotated-the other functions are 
not color-selectable). This is done so that the CRT Rotation can 
be properly performed without the influence of any previous 
corrections made for these adjustments. 
5. Loosen the 2 set screws (Figure 3-5) near the top of the CRT 
sleeve. 
6. Loosen the CRT Thumbscrew (Figure 3-5) on the top of the 
CRT Assembly.  
7. Tilt the yoke by grasping the Thumbscrew and moving it in 
whichever direction it takes to make the CRT raster square.  
8. When the CRT raster is square on the screen, tighten the 2 set 
screws first, then the CRT thumbscrew. 
9. In the Geometry menu, toggle the Reg Enable box back to On.  
10. Reset Bow, Pincushion, Keystone, and Skew (select proper 
color for Skew) to the values noted previously in Step 4. 
11. Recheck Bow, Pincushion, Keystone, and Skew and readjust if 
necessary. Also recheck Convergence (refer to the Model 200 
User’s Guide). 
12. Repeat the above procedure for any other CRT that is not level. 
3.7 CRT Electronic Focus 
The Electronic Focus is factory-set and will not normally need to be 
adjusted except after component replacement, maintenance, or if 
wide temperature variations exist between the factory and the field 
location. View one color at a time. 
1. Select the Focus test pattern. 
2. Zoom the Projection Lens to the widest angle and adjust the 
Projection Lens focus for the sharpest image. 
3. View Green. Hide Red and Blue. 
4. Adjust the Green Electronic Focus (Figure 3-6) for a sharp 
focus of the H pattern at the center of the screen. 
5. Repeat the above steps for Red and Blue. 
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Figure 3-6.   RGB Electronic Focus adjustments. 
3.8 ILA® Overlap 
This adjustment positions the ILA® assemblies in their sockets. 
Adjustment should only be made once or whenever an ILA® is 
replaced. 
To determine if this adjustment is necessary: 
1. Note the value of the ILA® bias for Red, Green and Blue so 
they can be returned to these levels when this procedure is 
complete.  
2. Hide all three colors. 
3. Increase the ILA® biases to maximum for all 3 colors. With all 3 
colors at maximum, the image on the screen should be a white 
screen with some colors at the edges. 
4. Observe the right, left, top, and bottom of the screen. Normally, 
green is the reference to which blue and red will be matched. 
(NOTE: If the green ILA® was replaced, the blue or red image 
should be used as the reference to which green is matched.) If 
a red or blue border is present on either side or at the top or 
bottom the ILA® overlap needs adjustment. If both red and blue 
overlap, the border will be yellow. In either case, proceed with 
the adjustment below. If there is no overlap, reset the ILA® 
biases to their previous levels from Step 2. 
To perform an ILA® Overlap adjustment: 
Remove the rear cover (Section 4.2) and tilt the electronic module 
up (Sections 3.3).  
1. Continue with all three colors hidden. 
2. Loosen the 2 wing nuts at the top of the ILA® assembly to be 
adjusted (Figure 4-12). 
3. 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. CAUTION! To avoid 
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damaging the connector, grasp the ILA® assembly itself, not 
the connector at the top. 
4. If the overlap is at the top or bottom, be sure the projector is 
level, then slide the spring clip (Figure 4-12) at the top of the 
ILA® assembly backward and remove the ILA® assembly (it will 
slide out with some resistance). There are two adjustment 
screws at the bottom of the ILA® assembly which allow for up 
and down movement. Turn these screws in or out very slightly 
to allow the ILA® to seat lower or higher, whichever is needed. 
5. Reinstall the ILA® assembly and replace the spring clip. 
6. Repeat Step 4 if adjustment is still needed. 
7. Retighten the 2 wing nuts. 
8. Reset the ILA® biases to their previous levels from Step 2. 
3.9 Front/Rear or Inverted Projection Jumper Settings 
3.9.1 Front/Rear Jumper Setting (Horizontal Reverse) 
The Horizontal Scan Reversal Jumper reverses the image 
projection for front or rear projection. Figure 3-7 illustrates the 
jumpers’ location on the Scan Reversal Board, and the proper 
location for front and rear projection.  
The projector is shipped with the jumper plugs inserted in J50 and 
J100 for front projection. For a rear projection setup, these jumpers 
must be inserted into JA50 and J101. 
 
HORIZ SIZE COILS 
Figure 3-7.   Scan Reversal Board. 
To set the Horizontal Scan Jumper: 
1. Turn power off at the projector and wait for the arc lamp to cool. 
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