Hughes JVC 220, Service Manual

Page: 87 / 140

Chapter 3 Service Adjustments
Figure 3-7. Scan Reversal Board.
To set the Horizontal Scan Jumper:
1. Turn power off at the projector and wait 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
projection or J50 and J100 for front projection ( See Figure 3-7 ).
Change jumper if necessary.
4. Replace the projector cover.
5. When changing jumpers for front or rear screen projection,
Centering, convergence and shading must be rechecked.
3.9.2 Inverted Vertical Jumper Setting
The Ceiling/Floor jumpers invert the image vertically for use in
some situations that use mirrors or ceiling projections. Figure 3-6
illustrates the location of the jumpers on the Scan Reversal Board
and indicates the proper location for ceiling or floor projection. The
Model 220 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 J53A. (
Refer to
Figure 3-7 ).
To invert the vertical image:
1. Turn power off at the projector and wait for the arc lamp to cool.
2. Remove the projector rear cover (Section 4.2).
3. Tilt the electronic module up (Section 3.3).
3-12 Model 220 Service Manual