Gma 35 Troubleshooting; Table 5-13. Gma 35 Troubleshooting - Garmin GTN 6XX System Maintenance Manual

5.4 GMA 35 Troubleshooting

This section provides information to assist troubleshooting if problems occur after completing
maintenance. Refer to the system configuration log retained in the aircraft permanent records for a list of
interfaced equipment and system configuration data.
Problem
Audio volume, audio routing,
music, marker beacon status,
or intercom are not working
properly.
Audio panel operates only in
failsafe mode (pilot headset
connected to one COM radio,
red X over the audio panel
control field).
190-01007-A1
Rev. 5

Table 5-13. GMA 35 Troubleshooting

Possible Cause
GMA 35 is not configured properly.
GMA 35 is disconnected from aircraft
power or ground.
GMA 35 is not seated correctly.
RS-232 communication between the
GTN 7XX and the GMA 35 is not
functioning correctly.
System Maintenance Manual GTN 6XX/7XX Part 23 AML STC
Corrective Action
Check the configuration
against the configuration log to
ensure that the GMA 35 is
configured properly.
Ensure power is connected to
P3502, pins 8 and 9, and
ground is connected to P3502,
pins 10 and 11. Check circuit
breakers and avionics switch.
Verify that the GMA 35 is fully
seated. Verify that counter-
sunk flathead screws are used
to secure the GMA 35
connectors to the backplate.
Check for proper configuration
of the GTN and GMA 35
RS-232 ports.
Check for correct wiring
between the audio panel and
the GTN 7XX.
Page 5-19