_________________________________________________________________
Page
3
‐
8
GMA
347
Maintenance
Manual
Rev.
A
190
‐
00325
‐
02
4.
Check
Pilot
and
Copilot
ICS
positions
for
isolation
and
proper
operation
of
volume
and
squelch
controls.
3.2.6
Aircraft
Receivers
Check
Select
the
audio
source
corresponding
to
each
installed
avionics
unit
and
check
for
audio
over
the
headsets.
3.2.7
Music
System
Check
1.
Set
the
intercom
to
the
ALL
mode
[Pilot
ISO
LED
off].
2.
Connect
a
stereo
audio
source
to
MUSIC
1
(ensure
the
front
panel
jack
is
empty
and
the
music
volume
knob
is
not
set
to
minimum).
Verify
that
stereo
audio
is
heard
over
all
headset
positions
when
MUSIC
1
is
selected
as
the
music
source
and
MUSIC
LED
is
on.
Pull
out
on
the
right
side
small
knob
and
verify
that
music
volume
adjustment
is
working
properly.
3.
Select
an
audio
source
to
COM
1
and
verify
that
the
sound
is
muted
by
active
COM
1
audio
when
RADIO
music
mute
is
selected
and
by
intercom
audio
when
ICS
music
mute
is
selected.
4.
Connect
a
stereo
music
source
to
MUSIC
2.
Verify
that
stereo
audio
is
heard
when
MUSIC
2
is
selected
as
the
music
source
and
MUSIC
LED
is
on.
5.
Connect
a
stereo
audio
source
to
the
front
panel
jack.
Verify
that
stereo
audio
is
heard
when
MUSIC
1
is
selected
as
the
music
source
and
MUSIC
LED
is
on.
This
completes
basic
troubleshooting.
NOTE
Adjustment
to
the
volume
and
squelch
settings
can
be
made
to
the
GMA
347
through
access
holes
in
the
unit’s
top
cover.
Refer
to
Section
2.3
of
the
GMA
347
Installation
Manual
(P/N
190
‐
00917
‐
01)
for
details.
