Hughes Model 230 Projector Service Manual

							Chapter 3---Service Adjustments
Model 230 Service Manual3-9
the four back screws (Figure 3-9), first remove the Condensing Lens by
removing the two X translation screws (Figure 3-8), then very slightly loosen
the four back screws until the lens can move freely in the up or down direction
by turning the Y translation screw. Then replace the Condensing Lens.
 
 Figure 3-9.  Condensing Lens, rear view.
 
7.  Remove the fan from the Dichroic Shield cover to provide access to the
Condensing Lens adjustments, then replace the Dichroic Shield cover but do
not secure it with the screws until the Condensing Lens adjustment is
completed later in this procedure.
 
 WARNING!!! The next step reapplies power to the projector.
Dangerous light exists in the mirror area where the Dichroic Shield cover was
removed. It is crucial that hands and other parts of the body be kept away
from the Arc Lamp light beam. Severe burns can result from even short
exposures to the light beam. Do not allow anyone near the projector unless
they are wearing safety goggles of at least X5 strength. Do not look directly at
the light beam even with safety goggles! PUT ON SAFETY GLASSES NOW!
8.  Apply power to the projector.
9.  Adjust the X (horizontal) position of the Condensing Lens to center the hot
spot horizontally. Do this by physically moving the lens horizontally until the
hot spot is centered horizontally on the screen.
10. Adjust the Y (vertical) position of the Condensing Lens to center the hot spot
vertically. Do this by adjusting the Y translation screw (Figure 3-8) until the
hot spot is centered vertically on the screen.
Back screws 
						

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3-10Model 230 Service Manual
11. Repeat Steps 9 and 10 until no further increase in center brightness can be
achieved and the hot spot is centered as much as possible.
12. When the hot spot is centered as much as possible, turn off power at the
circuit breaker. Wait 10 minutes for the components to cool down, then
carefully tighten the Condensing Lens locking screw, back screws, and X-
translatlon screws, replace the fan in the Dichroic Shield cover and replace
the Dichroic Shield cover in the projector.
13. Recheck rolloff with a light meter and readjust, if necessary, the Arc Lamp
alignment screws for a 4:1 rolloff from screen center to screen corners.
14. Close the fan door of the Arc Lamp Enclosure, replace the lower-right side
panel and front cover.
3.2 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.
3.3 ILA® Back Focus
The 
ILA® Back Focus adjustment moves the 
ILA®/Relay Lens/CRT assemblies
together to adjust the focal length. When using a zoom lens this adjustment
allows the zoom lens’ tracking to remain focused throughout the entire range. Use
the focus test pattern 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 2 people. One person
to watch the screen close-up and the other to 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 for a Zoom Lens:
1.  Remove the rear cover (Section 4.2).
2.  Tilt up the Electronic Module (Section 3.3).
3.  View Green. Hide Red and Blue.
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).
7.  Use left and right arrows to focus the projection lens to get sharply focused
spacer balls. 
NOTE: Spacer balls are used inside the ILA® Assembly to 
						

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Model 230 Service Manual3-11
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).
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 3-10). Move the CRT snug against the collar to get
additional range, and then, retighten the collar.
10. Loosen the 2 hex bolts (shown in Figure 3-12) 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 9-13 above for other colors that need 
ILA® Back Focusing. Be
sure to hide the other 2 colors.
To adjust the 
ILA® Back Focus for a Fixed Lens:
1.  Remove the rear cover (Section 4.2).
2.  Tilt up the Electronic Module (Section 3.3).
3.  View Green. Hide Red and Blue.
4.  Select the Focus test pattern.
5.  Select Projection Lens from the menu.
6.  Use left and right arrows to focus the projection lens to get sharply focused
spacer balls. 
NOTE: 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.
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 (Figure 3-10). Move the CRT snug against the collar to get
additional range,then retighten the collar. 
						

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3-12Model 230 Service Manual
8.  Loosen the 2 hex bolts (shown in Figure 3-12) on the 
ILA® assembly in front
of the Relay Lens.
9.  Slide the Relay Lens/CRT/ILA® assembly forward or backward until the
sharpest spacer ball focus is achieved. 
NOTE: Do not use the 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 2 colors.
NOTE: The CRT Mechanical Focus procedure (
Section 3.4) is often
performed sequentially with the CRT Rotation procedure (
Section 3.5). The
same two set screws (
Figure 3-10) are loosened when doing either of these
procedures. When performing the procedures in sequence, ensure the two
set screws are secured 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. 
Adjusting either of these while the set screws are loose may
cause the CRT to go out of focus or rotate.
3.4 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 full up position (Section 3.2).
3.  Select the Focus test pattern.
4.  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.
5.  Loosen the two set screws (Figure 3-10) 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 3-10). The CRT is now free to slide.
7.  Grasp the CRT thumbscrew (Figure 3-10) 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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Model 230 Service Manual3-13
Figure 3-10.   CRT Mechanical Focus adjustments.
3.5 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 (Section
3.2).
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.
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 
						

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3-14Model 230 Service Manual
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 3-10) near the top of the CRT sleeve.
6.  Loosen the CRT Thumbscrew (Figure 3-10) 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 230 User’s Guide).
12. Repeat the above procedure for any other CRT that is not level.
3.6 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 3-11) 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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Model 230 Service Manual3-15
Figure 3-11.   RGB Electronic Focus adjustments.
3.7 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 red, green, and blue.
3. Increase the 
ILA
® biases to maximum for all 3 colors. With all 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
3.2).
1.  Continue with all three colors hidden.
2.  Loosen the 2 wing nuts at the top of the 
ILA
® assembly to be adjusted (Figure
3-12).
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 damaging the connector, grasp the 
ILA®
assembly itself, 
not the connector at the top. 
						

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3-16Model 230 Service Manual
 
 Figure 3-12.  ILA® Assembly top view. The overlap screws shown are 
visible after the 
ILA® assembly is removed.
4.  If the overlap is at the top or bottom, be sure the projector is level, then slide
the spring clip (Figure 3-12) at the top of the 
ILA® assembly backward and
remove the 
ILA® assembly (it will slide out with some resistance). Observe
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.
3.8 Front/Rear or Inverted Projection Jumper Settings
NOTE: 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.
3.8.1   Front/Rear Jumper Setting (Horizontal Reverse)
1.  The Horizontal Scan Reversal Jumper reverses the image projection for front
or rear projection. Figure 3-13 illustrates the jumpers’ location on the Scan
Reversal Board.
2.  The Model 230 Projector is shipped with the jumper plugs inserted in J50 and
J100 for front/upright projection. For other orientations refer to Table 3-1. 
						

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Model 230 Service Manual3-17
Figure 3-13.   Scan Reversal Board.
To set the Horizontal Scan Jumper:
1.  Turn power off at the projector and wait 10 minutes for the arc lamp to cool.
2.  Remove the projector rear cover (Section 4.2).
3.  Verify that the jumper is plugged into JA50 and J101 for rear/upright
projection or J50 and J100 for front/upright projection (See Figure 3-13).
Refer to Table 3-1 for other orientations. Change jumpers if necessary.
4.  Replace the projector cover.
5.  When changing jumpers for front or rear screen projection, Centering,
convergence and shading must be rechecked.
 TABLE 3-1.   PROJECTION ORIENTATION JUMPER SETTINGS.
ORIENTATIONCONVERGENCE. P50
GOES TO:VERTICAL. P53
GOES TO:HORIZONTAL. P100
GOES TO:
FRONT/FLOOR
UPRIGHTJ50 J53 J100
FRONT/CEILING
UPSIDE DOWNJA50 JA53 J101
REAR/FLOOR
UPRIGHTJA50 J53 J101
REAR/CEILING
UPSIDE DOWNJ50 JA53 J100 
						

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3.8.2   Inverted Vertical Jumper Setting
The Ceiling/Floor jumpers invert the image vertically for use in some situations
that use mirrors or ceiling projections. Figure 3-13 illustrates the location of the
jumpers on the Scan Reversal Board. The Model 230 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. (Refer to
Table 3-1 for other orientations).
To invert the vertical image:
1.  Turn power off at the projector and wait for the arc lamp to cool.
2.  Remove the projector rear cover (Section 4.2).
3.  Tilt the electronic module up (Section 3.2).
4.  Verify that the vertical jumper is inserted in the correct jacks for appropriate
application, (refer to Figure 3-13 and Table 3-1).  Change jumpers if
necessary.
5.  Replace the electronic module and rear cover.
6.  When changing jumpers for floor or ceiling screen projection, Centering,
Convergence and Shading must be rechecked.
3.9 Vertical and Horizontal Size Settings
Adjust the vertical height pots and horizontal size coils when replacing the
Horizontal/Vertical Deflection board, Scan Reversal board, or CRT/Yoke
assembly. These adjustments may also be needed when the convergence
adjustment procedures fail to bring the colors into convergence.
Figure 3-14. Horizontal/Vertical Deflection Board.