_________________________________________________________________
GMA
347
Maintenance
Manual
Page
3
‐
1
190
‐
00325
‐
02
Rev.
A
SECTION
3
TROUBLESHOOTING
This
section
contains
basic
tests
which
can
be
used
to
troubleshoot
and
confirm
a
defective
unit.
All
tests
are
conducted
with
covers
in
place.
There
is
no
calibration
or
alignment
of
the
Audio
Panel.
3.1
TEST
CONDITIONS
3.1.1
Test
Setup
Recommended
Test
Equipment
Standard
avionics
shop
equipment
(or
suitable
substitutes)
is
used
to
test
the
unit.
Test
bench
harnesses,
test
fixtures,
and
test
panels
are
supplied
by
the
field
shop.
Rear
chassis
connector
pin
information
can
aid
in
their
fabrication
(Figure
3
‐
1,
Tables
1
‐
1
and
1
‐
2).
3.1.2
Rear
Chassis
Connectors
Figure
3
‐
1
shows
the
J3471
(audio
board)
and
J3472
(main
board)
connectors.
Tables
3
‐
1
and
3
‐
2
lists
their
pin
assignments,
names,
and
functions.
