Installation manual

Dolby
®
Model CP650 Troubleshooting Chart Maintenance and Troubleshooting
9-15
Symptom Probable Cause Recommended Action
There is distortion when you play non- sync sound, but sound from the film is not distorted.
The nonsync source is introducing distortion. Excessive output level from nonsync source. Defective Cat. No. 772 board.
Change the nonsync selection (in case the track being played is distorted). If you have control of the output level of the nonsync device (cassette deck, CD player, etc.), turn down its output level, especially if you have to operate the nonsync with the fader set far below 7. If this does not help, try a different device. If changing both the device and the selection does not eliminate the distortion, the problem is in the CP650, probably on the Cat. No. 772 board. Call service engineer.
Nonsync sound is heard in other formats.
The nonsync source output level is set far too high or there is a balanced/unbalanced wiring problem.
Turn down nonsync source level if possible and call service engineer. If turning the nonsync source down doesn’t correct the problem, turn it off during the show.
Sound from a mono film is distorted, as is sound from the center channel of a stereo film.
Malfunctioning power amplifier. Malfunctioning loudspeaker.
Interchange power amplifiers to determine if distortion is still present. Interchange speakers to determine if distortion is still present.