Arc Lamp Current Setting - Hughes JVC 220 Service Manual

Chapter 3 Service Adjustments
Figure 3-3. Arc Lamp "Hot Spot" (whitest area) is off-center vertically and
horizontally. Adjust to center the "hot spot".
3.2

Arc Lamp Current Setting

3-4
F. Reapply power to the projector.
G. CAUTION! The First Condensing lens may still be hot!
Using a small, flathead screwdriver, adjust the horizontal or
vertical screw (Figure 3-1) on the First Condensing Lens
Retainer Ring to center the "hot spot" on the screen.
H. Retighten the 3 retainer ring screws (Figure 3-1).
7. Adjust the focus screw for overall brightness from the center to
the edges with minimum rolloff. NOTE: Rolloff is the gradual
difference in brightness from the center of the screen to the
edges. Ensure the bright area extends to the edges of the
screen but not over the edges. If possible, use a light meter to
perform this step. If using a light meter, try to achieve a rolloff
of 2:1 but no more than 4:1 to the screen corners. The darker
areas in each of the corners should be balanced evenly.
8. When the Arc Lamp is focused over the entire screen area,
reset the Green ILA® bias to original value noted in step 4.
The Arc Lamp current must be set whenever an Arc Lamp or Arc
Lamp Power Supply is replaced. Routinely recheck current about
Model 220 Service Manual