Hughes JVC Projector 230 Sc 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,...

Chapter 3 Service Adjustments
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...

Chapter 3---Service Adjustments
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...

Chapter 3 Service Adjustments
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...

Chapter 3---Service Adjustments
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...

Chapter 3 Service Adjustments
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...

Chapter 3---Service Adjustments
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...

Chapter 3 Service Adjustments
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...

Chapter 3---Service Adjustments
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...

Chapter 3 Service Adjustments
3-18Model 230 Service Manual
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...