Dolby Laboratories CP650 Installation Manual download pdf (Page 72)

Dolby

CP650 Installation Manual A-Chain Alignment

5-2

5.1 Projector Checkup

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.

5.2 Projector Analog Optical Alignment

If a stereo solar cell is already installed on projector 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. 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 it 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. Install a new lens assembly if

necessary.

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.

Remove the existing exciter lamp and replace with a new lamp. Adjust the exciter

lamp DC voltage to between 70 and 85 percent of the rated voltage. Using an AC

millivolt meter or oscilloscope, verify that there is no more than 3 percent ripple

present with the lamp on.

LAMP VOLTAGE DC ADJUSTMENT

6 V 4–5 V

9 V 6.5–8 V

If the projector uses a plastic light pipe or tube, verify that the light output is not

appreciably affected by dirt, cracks, flaws, yellowing, or foreign matter. Replace if

necessary.

1 2 ... 67 68 69 70 71 72 73 74 75 76 77 ... 165 166

No comments

Dolby Laboratories CP650 Installation Manual Page 72