Ila ® Overlap - Hughes JVC 220 Service Manual

Chapter 3 Service Adjustments
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3.8 ILA
3-10
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.
Figure 3-6. RGB Electronic Focus adjustments.
Overlap
This adjustment positions the ILA
Adjustment should only be made once or whenever an ILA
replaced.
To determine if this adjustment is necessary:
1. Note the value of the ILA
they can be returned to these levels when this procedure is
complete.
2. Hide all three colors.
3. Increase the ILA
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
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
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bottom the ILA
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.
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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.
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assemblies in their sockets.
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bias for Red, Green and Blue so
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biases to maximum for all 3 colors. With all 3
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was replaced, the blue or red image
overlap needs adjustment. If both red and blue
Model 220 Service Manual
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is
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