3M 478DA (D-15) User manual

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Troubleshooting Guide
Model 478DA (D-15)
Single Intercom System
Introduction
The Model 478DA is a single-channel intercom system that is used for point-to-point communication applications.
The system includes a visible/audible presence alert and the capability of multiple units communicating with the same
loudspeaker.
Problem Isolation Procedure
Use the troubleshooting table on the following pages to help isolate the problem:
1. Start at the top of the table and work down to the bottom.
2. For each symptom listed, determine if it applies to the situation.
3. If a symptom does apply, check (ü) the box adjacent to the symptom.
4. Read across the table to the possible causes and corrections listed in the middle and right columns.
5. Investigate these possible causes and implement the corrections. Possible causes are listed in the order in which
they are most likely to occur.
If none of the possible causes and corrections applies to the situation, call 3M Media InTouch and review the
"checked" symptoms with the technical support staff.

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 Standby Touch Switch Silences intercom audio to eliminate pickup of undesired
background noise and reconnects optional music/message
source to the external speaker when unit is not in use. The
system automatically exits the standby mode with vehicle
detection or when the Touch/Talk switch is pressed.
4 Touch/Talk Switch Controls talk/listen communications. Operator touches switch
to talk and cancel alert tone. Operator releases switch to
listen.
5 Indicator Lights Red indicates TALK mode.
Green indicates LISTEN mode.
Yellow indicates vehicle presence.
Yellow light above STANDBY lights and all other lights are
extinguished when the system is placed in the standby mode.

Model 478 (D-15) Technician Troubleshooting Guide
3
Troubleshooting Table
Problem Possible Cause Correction
No inbound audio. Power
Indicator Light (green) is
OFF.
No AC power to the unit. Check power supply
transformer or wall outlet.
Defective analog board. Check and replace analog
board.
No inbound audio:
•Power Indicator Light
(green) is ON.
•LISTEN Indicator Light
(green) is OFF.
Defective logic board or
touch pad. Check and replace logic board or touch pad.
No inbound audio:
•Power Indicator Light
(green) is ON.
•LISTEN Indicator Light
(green) is ON.
Defective menu speaker,
menu mic, or wiring. Check and replace menu speaker, menu mic, or wiring.
Defective analog board. Check and replace analog
board.
Inbound audio distorted. Defective menu speaker,
menu mic, or wiring. Check and replace menu speaker, menu mic, or wiring.
Defective analog board. Check and replace analog
board.
No outbound audio. Power
Indicator Light (green) is
OFF.
No AC power to the unit. Check power supply
transformer or wall outlet.
Defective analog board. Check and replace analog
board.
No outbound audio:
•Power Indicator Light
(green) is ON.
•TALK Indicator Light
(red) is OFF when TALK
SWITCH is pressed.
Defective logic board or
touch pad. Check and replace logic board or touch pad.
(continued)

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 TALK
SWITCH is pressed.
Defective menu speaker,
menu mic, or wiring. Check and replace menu speaker, menu mic, 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.
Alert volume control setting
too low. Check and/or increase the Alert volume control setting
on bottom of unit.
Defective analog board. Check and replace analog
board.
With car on loop, VEHICLE
Indicator Light (yellow) is
OFF, and vehicle detection
tone does not sound.
Defective logic or analog
board. Check and replace logic or analog board.
Outbound audio distorted. Defective analog board. Check and replace analog
board.
Defective internal
microphone. Replace microphone.
Defective menu sign
speaker. Replace menu sign speaker.
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3M Media InTouch
3M Center, Building 551-1E-02
St. Paul, MN 55144-1000
Printed on 50% recycled paper,
including 10% post-consumer waste.
Printed in U.S.A.
© 3M 1997 January
78-6912-0660-7 Rev. A

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Troubleshooting Guide
Model 481 BA(D-20) 6-Channel Intercom System
Introduction
The Model 481 is a 6-channel intercom system that is typically used to provide communication between store
counters and pump islands in self-service gas stations, convenience stores and truck stops.
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Intracom D-20
VOLUME
OFF ON
SP-206A
Problem Isolation Procedure
Use the troubleshooting table on the following pages to help isolate the problem:
1. Start at the top of the table and work down to the bottom.
2. For each symptom listed, determine if it applies to the situation.
3. If a symptom does apply, check (ü) the box adjacent to the symptom.
4. Read across the table to the possible causes and corrections listed in the middle and right columns.
5. Investigate these possible causes and implement the corrections. Possible causes are listed in the order in which
they are most likely to occur.
If none of the possible causes and corrections applies to the situation, call 3M Media InTouch and review the
"checked" symptoms with the technical support staff.

Technician Troubleshooting Guide Model 481BA (D-20)
2
3
Intracom D-20
VOLUME
OFF ON
SP-205A
98
76
5
41
2
3
Figure 1. Operating Controls
Key Control Name Function
1 Power Switch Provides power to mainstation.
2 Power Indicator Light Indicates power is on and the system is ready to operate.
3 Volume Control Adjusts INCOMING audio level.
NOTE: Volume level adjustments for alert tone and outside
speakers are set by the installer.
4 Channel Selector Switches (1-6) These switches control talk/listen communication for
numbered channels. Operator touches switch to talk and
releases switch to listen.
5 Indicator Lights Red indicates TALK mode.
Green indicates LISTEN mode.
Yellow (steady) indicates channel on "HOLD."
Yellow (flashing) indicates incoming call WAITING.
6 Hold Switch Places selected channel in "HOLD" mode.
7 All Call Switch Controls conversation with all channels simultaneously.
8 Standby Switch Silences incoming audio to eliminate undesired background
noise pickup when unit is not in use. Touching any
CHANNEL SELECTOR SWITCH releases STANDBY
mode.
9 Standby Indicator Light Indicates unit is in STANDBY mode.

Model 481BA (D-20) Technician Troubleshooting Guide
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Troubleshooting Table
Problem Possible Cause Correction
No inbound audio. Power
Indicator Light (green) is
OFF.
No AC power to the unit. Check power supply
transformer or wall outlet.
No inbound audio:
•Power Indicator Light
(green) is ON.
•LISTEN Indicator Light
(green) is OFF.
Defective logic board or
touch pad. Check and replace logic board or touch pad.
No inbound audio:
•Power Indicator Light
(green) is ON.
•LISTEN Indicator Light
(green) is ON.
Defective speaker/mic or
analog board. Check and replace speaker or analog board.
Inbound audio distorted. Defective speaker/mic or
analog board. Check and replace speaker/mic or analog board.
No outbound audio:
•Power Indicator Light
(green) is ON.
•TALK Indicator Light
(red) is OFF when TALK
SWITCH is pressed.
Defective logic board or
touch pad. Check and replace logic board or touch pad.
No outbound audio:
•Power Indicator Light
(green) is ON.
•TALK Indicator Light
(red) is ON when TALK
SWITCH is pressed.
Defective speaker/mic or
analog board. Check and replace speaker/mic or analog board.
The VEHICLE Indicator
Light (yellow) blinks, but
vehicle detection tone does
not sound.
Alert volume too low. Check and adjust alert
volume control on analog
board.
Defective analog or logic
board. Check and replace analog or logic board.
(Continued)

Technician Troubleshooting Guide Model 481BA (D-20)
Problem Possible Cause Correction
The VEHICLE Indicator
Light (yellow) is OFF and the
vehicle detection tone does
not sound.
Defective call switch. Check and replace call
switch.
Defective analog or logic
board. Check and replace analog or logic board.
Unit will not return to standby
mode when STANDBY
Switch is pressed.
Defective logic board. Check and replace logic
board.
Unit will not come out of
standby mode. Defective logic board. Check and replace logic board.
Outbound audio distorted. Defective analog board. Check and replace analog
board.
Defective internal
microphone. Replace microphone.
Defective outside speaker. Replace speaker.

3M Media InTouch
3M Center, Building 551-1E-02
St. Paul, MN 55144-1000
Printed on 50% recycled paper,
including 10% post-consumer waste.
Printed in U.S.A.
© 3M 1997 January
78-6912-0634-2 Rev. A

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Troubleshooting Guide
Model 479 (D-30) 2-Channel Intercom System
Introduction
The Model 479 is a 2-channel intercom system that is typically used to provide communication between store
counters and pump islands in self-service gas stations, convenience stores and truck stops.
Problem Isolation Procedure
Use the troubleshooting table on the following pages to help isolate the problem:
1. Start at the top of the table and work down to the bottom.
2. For each symptom listed, determine if it applies to the situation.
3. If a symptom does apply, check (ü) the box adjacent to the symptom.
4. Read across the table to the possible causes and corrections listed in the middle and right columns.
5. Investigate these possible causes and implement the corrections. Possible causes are listed in the order in which
they are most likely to occur.
If none of the possible causes and corrections applies to the situation, call 3M Media InTouch and review the
"checked" symptoms with the technical support staff.

Technician Troubleshooting Guide Model 479 (D-30)
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6
4
51
2
SP-208A
5
3
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 mainstation internal speaker (listen) audio level.
3 Talk Switches (A & B) Control talk/listen communication for the respective channel
(A or B). Operator touches switch to talk and releases switch
to listen.
4 Standby Switch Silences audio to eliminate pickup of undesired background
noise when unit is not in use. Touching either the Channel A
or Channel B Talk Switch releases STANDBY mode.
Vehicle Detection automatically places the system into the
Channel A listen mode.
5 Indicator Lights (same for Channel A and
Channel B) Red indicates TALK mode. Green indicates LISTEN mode.
Yellow indicates vehicle presence (when used with 3M
SODAR or magnetic loop detection system).
All indicator lights are extinguished when mainstation is in
the standby mode.
6 Standby Mode Switch AUTO (automatic) position causes system to switch from
Channel A Listen to Standby when there is no vehicle detect
signal. MAN (manual) position allows operator to use
Channel A without vehicle detection.

Model 479 (D-30) Technician Troubleshooting Guide
3
Troubleshooting Table
Problem Possible Cause Correction
No inbound audio. Power
Indicator Light (green) is
OFF.
No AC power to the unit. Check power supply
transformer or wall outlet.
Defective analog board. Check and replace analog
board.
No inbound audio:
•Power Indicator Light
(green) is ON.
•LISTEN Indicator Light
(green) is OFF.
Defective logic board or
touch pad. Check and replace logic board or touch pad.
No inbound audio:
•Power Indicator Light
(green) is ON.
•LISTEN Indicator Light
(green) is ON.
Defective menu speaker,
menu mic, or wiring. Check and replace menu speaker, menu mic, or wiring.
Defective analog board. Check and replace analog
board.
Inbound audio distorted. Defective menu speaker,
menu mic, or wiring. Check and replace menu speaker, menu mic, or wiring.
Defective analog board. Check and replace analog
board.
No outbound audio. Power
Indicator Light (green) is
OFF.
No AC power to the unit. Check power supply
transformer or wall outlet.
Defective analog board. Check and replace analog
board.
No outbound audio:
•Power Indicator Light
(green) is ON.
•TALK Indicator Light
(red) is OFF when TALK
SWITCH is pressed.
Defective logic board or
touch pad. Check and replace logic board or touch pad.
(continued)

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
SWITCH is pressed.
Defective menu speaker,
menu mic, or wiring. Check and replace menu speaker, menu mic, 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 vehicle detection
tone does not sound.
Defective logic or analog
board. Check and replace logic or analog board.
Outbound audio distorted. Defective analog board. Check and replace analog
board.
Defective internal
microphone. Replace microphone.
Defective menu sign
speaker. Replace menu sign speaker.

Food Services Trade Department
3M Center, Building 551-1E-02
St. Paul, MN 55144-1000
Printed on 50% recycled paper,
including 10% post-consumer waste.
Printed in U.S.A.
© 3M 1997 January
78-6912-0637-5 Rev. A