Installation manual

Dolby
®
Model CP650 Troubleshooting Chart Maintenance and Troubleshooting
9-9
Symptom Probable Cause Recommended Action
NO SOUND AT ALL No sound, front-panel dark, power button not glowing.
No power to either main or bypass systems. See if AC mains panel circuit breaker feeding the CP650 is tripped.
Verify that all power connectors are fully inserted into their sockets. Press main power button. If CP650 still does not come on, check fuse behind plastic door in AC mains power inlet module located on the rear of the unit.
No sound, and switching to Bypass doesn’t restore sound. OR No sound, front-panel dark, power button is illuminated, and system is already in Bypass.
Defective analog reader LED, exciter lamp, or LED/lamp power supply. Projector selection wire/switch is faulty. No signals coming from stereo solar cells. Power amplifiers switched off.
Check that the LED or exciter lamp is on. If not, fade up background music, transfer the reel to the alternative projector and continue the show until the LED/lamp or its power supply can be replaced. Call service engineer. If the front-panel indication (P1, P2) for the currently active projector
is not correct, check the projector selector switch wiring. In addition, check that the switch or relay is operating properly. Check that the signal-presence LEDs inside the setup panel access door are flashing while film is running. If not, there is no signal from the solar cells, or the Cat. No. 772 analog board has failed. Substitute a known, working Cat. No. 772 board. Check power feed to power amplifiers for blown circuit breaker or fuse or accidental disconnection.
No sound, front-panel normal. Check the causes listed above, plus wrong format
selected, system muted, or fader turned down.
Check same components as mentioned above. Then verify selected format, mute status, and fader setting. If no formats produce sound, there may be a CP650 internal problem. Call your local service engineer.