Technician Troubleshooting Guide Model 479 (D-30)
Problem Possible Cause Correction
No outbound audio:
•Power Indicator Light
(green) is ON.
•TALK Indicator Light
(red) is ON when TALK
SWITCHis pressed.
Defectivemenu speaker,
menu mic,or wiring. Check and replace menu
speaker, menumic, or wiring.
Defective analog board. Check and replace analog
board.
With car on loop, VEHICLE
Indicator Light(yellow) is
ON, but vehicle detection tone
does not sound.
Vehicle Detect-to-Main
signal too low. Adjust R6 to increase signal
level.
Defective analog board. Check and replace analog
board.
With car on loop, VEHICLE
Indicator Light(yellow) is
OFF, and vehicledetection
tone does not sound.
Defective logicor analog
board. Check and replace logicor
analog board.
Outbound audio distorted. Defective analogboard. Check and replace analog
board.
Defective internal
microphone. Replace microphone.
Defectivemenu sign
speaker. Replace menusign speaker.
FoodServices TradeDepartment
3MCenter, Building 551-1E-02
St.Paul, MN 55144-1000
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78-6912-0637-5 Rev. A