3M 478DA (D-15) - Manuals

Technician Troubleshooting Guide Model 478 (D-15) 2 Figure 1. Operating Controls Key Control Name Function 1 Power Switch Controls application of power to the system. Power Indicator Light Indicates power is applied to the system. 2 Volume Control Adjusts the internal speaker (listen) audio level. 3...

Model 478 (D-15) Technician Troubleshooting Guide 3 Troubleshooting Table Problem Possible Cause Correction No inbound audio. PowerIndicator Light (green) isOFF. No AC power to the unit. Check power supplytransformer or wall outlet. Defective analog board. Check and replace analog board. No inbound ...

Technician Troubleshooting Guide Model 478 (D-15) Problem Possible Cause Correction No outbound audio: • Power Indicator Light(green) is ON. • TALK Indicator Light(red) is ON when TALKSWITCH is pressed. Defective menu speaker,menu mic, or wiring. Check and replace menuspeaker, menu mic, or wiring. D...