Troubleshooting
Apollo CNX80 Installation Manual
560-0982-00 Rev D
4-1
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
P
ROCEDURE
Table 4-1. Troubleshooting Guide
Problem Possible
Cause
Solution
The CNX80 does not
power on.
•
The unit is not getting power to
the main connector P1.
•
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.
The CNX80 does not
compute a position.
•
Not receiving signals, or incorrect
seed position, time, and date.
•
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.
GPS signal levels drop
when avionics are
turned on.
•
Noise interference from other
avionics.
•
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.
The GPS signal levels
are very low.
•
Improper antenna installation or
coax routing.
•
Antenna shaded from satellites.
•
RF interference at 1575.42 MHz
from VHF com.
•
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.
Unable to control
Com using
COM
bezel key.
•
No power to the com.
•
The input voltage is too low.
•
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.
Summary of Contents for Apollo CNX80
Page 1: ...Apollo CNX80 Installation Manual September 2003 560 0982 00 Rev D...
Page 10: ...Table of Contents viii 560 0982 00 Rev D Apollo CNX80 Installation Manual NOTES...
Page 30: ...General Information 1 20 560 0982 00 Rev D Apollo CNX80 Installation Manual NOTES...
Page 114: ...Periodic Maintenance 6 2 560 0982 00 Rev D Apollo CNX80 Installation Manual NOTES...
Page 134: ...Appendix D Interconnect Diagrams D 2 560 0982 00 Rev D Apollo CNX80 Installation Manual NOTES...
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