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...

Chapter 3---Service Adjustments 
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...

Chapter 3 Service Adjustments 
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...

Chapter 3---Service Adjustments 
 
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)....

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...

Chapter 3---Service Adjustments 
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...

Chapter 3 Service Adjustments 
 
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...

Chapter 3---Service Adjustments 
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...

Chapter 3 Service Adjustments 
 
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...

Chapter 3---Service Adjustments 
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...