Table 4-1. Troubleshooting; P Rocedure - Garmin Apollo CNX80 Installation Manual

4 T
ROUBLESHOOTING
This section provides information to assist troubleshooting if problems occur after completing the
installation. Use Table 4-1 to assist in troubleshooting. Devices connected to the CNX80, such as an
SL30, SL70 or MX20 can be useful for determining whether the CNX80 is functioning properly or if there
are problems with the installation.
4.1 T
ROUBLESHOOTING
Problem
• The unit is not getting power to
The CNX80 does not
power on.
• Not receiving signals, or incorrect
The CNX80 does not
compute a position.
• Noise interference from other
GPS signal levels drop
when avionics are
turned on.
• Improper antenna installation or
The GPS signal levels
are very low.
• Antenna shaded from satellites.
• RF interference at 1575.42 MHz
• No power to the com.
Unable to control
Com using
COM
bezel key.
• The input voltage is too low.
Apollo CNX80 Installation Manual
P
ROCEDURE
Table 4-1. Troubleshooting Guide
Possible Cause
the main connector P1.
seed position, time, and date.
avionics.
coax routing.
from VHF com.
560-0982-00 Rev D
Solution
•
Make sure power is connected to the
main 37-pin connector P1-1 and 16 and
ground to P1-2 and 20. Check circuit,
breakers and main avionics switch.
•
Make sure a correct position and
time/date have been entered. Check the
GPS antenna connections. Make sure
the aircraft is clear of hangers,
buildings, trees, etc.
•
Turn all avionics off, then turn on each
piece one at a time to isolate the source
of the interference. Route GPS cable
and locate GPS antenna away from
sources of interference.
•
Check GPS antenna installation,
connections, and cable routing. The
GPS antenna must be mounted on the
top of the aircraft.
•
Make sure the aircraft is clear of
hangers, buildings, trees, etc.
•
Move GPS antenna further from the
com antenna. Add a 1575.42 MHz
notch filter in com coax. Fix or replace
the com. Disconnect the ELT antenna
coax to check for possible re-radiation.
•
Make sure power is connected to the
com 15-pin connector P4-1 and ground
to P4-9.
•
Increase input supply voltage to > 10
volts DC.
Troubleshooting
4-1