Troubleshooting; Troubleshooting Procedure; Table 6-1. Troubleshooting Guide - Garmin GNS 530W Installation Manual

6. TROUBLESHOOTING

This section provides information to assist troubleshooting if problems occur after completing the
installation. Devices connected to the GPS 500W/GNS 530W can be useful for determining whether the
500W Series unit is functioning properly or if there are problems with the installation.

6.1 Troubleshooting Procedure

Problem
• The unit is not getting power to
The 500W Series
unit does not power
on.
• Not receiving signals.
The 500W Series
unit does not
compute a position.
• Noise interference from other
GPS signal levels
drop when avionics
are turned on.
• Improper antenna installation
The GPS signal
levels are very low.
• Antenna shaded from satellites. • Make sure the aircraft is clear of
• RF interference at 1575.42
• The PTT input is not being
The 500W Series
unit does not
transmit.
• No transmit power to the
• The input voltage is too low.
500W Series Installation Manual
190-00357-02

Table 6-1. Troubleshooting Guide

Possible Cause
the main connector P5001.
avionics.
or coax routing.
MHz from VHF COM.
pulled low.
COM.
Solution
• Make sure power is connected to the
main 78-pin connector P5001, pins
19 and 20 and ground to P5001, pins
77 and 78. Check circuit breakers
and main avionics switch.
• Check the GPS antenna connections.
Make sure the aircraft is clear of
hangars, buildings, trees, etc.
• Wait 20 minutes for unit to complete
cycle.
• 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.
hangars, 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.
• Check that the PTT (mic key) input is
pulled low for transmit.
• Make sure power input is connected
to the COM 25-pin connector P5002
11 and 12 and ground to P5002 21
and 22.
• Increase input supply voltage to
>12VDC. (>24VDC for 530AW
models)
Page 6-1
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