Dolby
®
Model CP650 Installation Manual
A-Chain Alignment
5-2
5.2
Reverse-Scan Checkup: Projector
Clean the optical surfaces with a cotton swab moistened with glass cleaner. Inspect
the film guides for evidence of cuts, cracks, surface defects, or any foreign materials
that could impair smooth film guiding.
5.3
Analog Optical Alignment: Projector
If a stereo solar cell is already installed on
Projector No. 1, inspect the surface of the cell
for cracks, chipping, or other damage. If the
cell appears to require replacement, remove the
mounting bracket from the projector and
replace the cell and mounting block assembly.
Clean the lens surfaces with a cotton swab
moistened with glass cleaner. But keep in mind
that you may find, during optical preamp
adjustment, that it will be necessary to remove
and inspect the lens if the high-frequency
response is not correct.
If the lens is removed, clean the lens as
indicated above and look through the lens at a
light. Repeated heating and cooling of the lens
can cause oil or other contaminants to enter the
lens barrel. Verify that there is a clear,
unobstructed light path through the lens and
that the edges of the slit are sharp without
cracks or corrosion. Fit a new lens assembly if
you are unable to clear the optical path through
the slit.
Inspect the lateral film guides for evidence of
cuts, cracks, surface defects, or any foreign
materials that could impair the film guiding.
Clean or replace the guides as necessary. The
guide roller must rotate freely; if it is spring-
mounted, make sure that lateral movement and
return are not obstructed. If the roller has a felt
or rubber insert, check for a flat spot and
replace the roller if necessary.
