Installation manual

Dolby
®
Model CP650 Troubleshooting Chart Maintenance and Troubleshooting
9-13
Symptom Probable Cause Recommended Action
TROUBLE IN ONE OR MORE CHANNELS One channel fails. Defective power amplifier, external crossover, or
wiring for that channel. Power amplifier input level setting turned down. Malfunctioning board in CP650.
Place the CP650 in bypass. All three screen speakers should become active. If not, there is a fault in the power amplifier, external crossover, or wiring for the missing channel. Check whether the amplifier is on and check for blown fuses. Check that the power amplifier volume control setting has not been changed. Check that the wiring from the CP650 to the amplifier or the loudspeaker wiring has not been broken or disconnected. If the power amplifier and the wiring are satisfactory, the problem may be a malfunctioning circuit in the CP650. Switch to bypass and call service engineer.
The sound from one channel is distorted and you can hear the distortion through the booth monitor at normal listening level.
Defective power amplifier for that channel. Defective speaker for that channel. (The booth sound is OK but sound in the auditorium is bad). Malfunctioning Cat. No. 772 board in CP650. Wiring from the stereo solar cell to the CP650.
Check that the amplifier is on and the fuses are OK. Check speaker. Call service engineer. Check that the wiring from the stereo solar cell to the CP650 has not become damaged and that the solder connections to the fanning strip are secure. Check that the D-connector for the solar cell is firmly plugged into the CP650. Call service engineer if wiring problems are found.