User`s manual

Dolby
®
CP650 Digital Cinema Processor User’s Manual
3-1
Chapter 3
Maintenance and Calibration
Having the very best equipment in your installation does not in itself guarantee that
you will always achieve the best results. A number of routine maintenance and
adjustment procedures, requiring no special test equipment or technical knowledge,
are necessary to realize the full potential of the sound system on a day-to-day basis.
These procedures can also prevent costly show cancellations and service calls.
A Dolby
®
Cat. No. 69T test film is required for proper maintenance of your sound
system. We also recommend that you keep on hand the Dolby Cat. No. 251 Jiffy test
film, and run it regularly to check the theatre sound system thoroughly (see
Appendix C).
3.1 Soundhead Maintenance
No single maintenance procedure is more vital to good sound in the theatre than
regular cleaning of the projector soundhead optics. A clean soundhead keeps your
theatre sounding its best.
3.1.1 Analog Sound System
Use lint-free cotton swabs and window or glass cleaner to clean the optical barrel lens
surfaces.
If your system uses a solar cell, it can be cleaned by gently using a dry cotton swab.
The solar cell and its adjustments are extremely delicate. Alternatively, careful use of
compressed air can blow dirt and debris away from the cell. Be very careful that the
nozzle or tube end never touches the cell. The spray can crack it.
3.1.2 Digital Sound System
The digital soundhead, like the analog soundhead, should be kept clean for best
performance. Wiping the external surfaces with a clean cloth on a regular basis will
keep the soundhead looking new. The optical path should be inspected regularly and
kept dust free with a photographer’s lens-cleaning kit (available from most camera
stores). Take care not to scratch the lens. The film path (rollers and drum) should be
cleaned regularly, as you would on the projector. Acetone, carbon tetrachloride, and
other dangerous cleaners should not be used.
3.1.3 Replacing the Cat. No. 700 Digital Soundhead Exciter Lamp
If your system uses the earlier Cat. No. 700 Digital Soundhead, the exciter lamp
needs occasional replacement. It is designed for long life and should provide more
than 8,000 hours of reliable use under normal circumstances. Routine replacement