JVC M100
Service Manual

Chapter 3---Service Adjustments

18. Adjust the Z-Axis to increase light output. Use either a 10mm socket or a 5mm hex wrench (see Figure 3-6). 19. When the desired light output is achieved, tighten the 4 retaining screws. 20. When proper rolloff is obtained, return the ILA® bias adjustment to the level from Step 4, and recheck the "Shutters on Hide" box.

Loosen these screws for Z-Axis adjustment (two more screws under the Arc Lamp Module)

Z-Axis Adjustmen t

Figure 3-6 Arc Lamp Z-Axis adjustment.

3.3 ILA® Back Focus
The ILA® Back Focus adjustment moves the CRT/ ILA® assemblies together to adjust the focal length so that the image will be focused on the screen. When using a zoom lens this adjustment allows the zoom lens� tracking to remain focused throughout the entire range. Use the Pluge/Grey 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. To adjust the ILA® Back Focus for a Zoom Lens: 1. 2. 3. 4. 5. Remove all the covers (seeSection 4.2). View the Green Channel. Hide the Red and Blue Channels. Select Test Pattern #7 (the Pluge/Grey test pattern). Select Projection Lens from the menu. Use the up/down arrow keys to zoom the Projection Lens to smallest image. 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
Model 100 Service Manual 3-9