Instruction Manual

Instructions for Continued Airworthiness 190-00792-12 Rev 1
for the Garmin G500H Installation in Eurocopter AS350 Page 66 of 80
4. Troubleshooting guide
If error indications are displayed on the GDU 620 display unit, consult the Troubleshooting section
contained in Table 31-11.
The G500H will display a number of alerts on the GDU 620 MFD. These are listed in the Table 31-12.
Table 31-13 GDU 620 Troubleshooting Guide
Problem Cause Solution
Unit does not power up –
blank screen.
Improper wiring; circuit breaker
open.
Ensure power is properly wired to the
GDU 620 and the circuit breaker is closed.
Unit intensity turned down. Ensure that unit is not in manual intensity
control mode with the intensity turned
down.
All expected configuration
pages are not displayed.
An Installer Unlock Card is not
inserted into the GDU 620.
Insert the Installer Unlock Card
P/N 010-00769-
60 into the bottom slot of
the GDU 620 and cycle power.
The GDC OAT probe type
shows up as UNKNOWN
The RS-232 connection to the
GDC 74H is not working.
Ensure that the GDC 74H RS-232
connection to the GDU is properly wired,
and ensure that the GDC 74H circuit
breaker is closed.
When loading software, the
LRU software is not being
displayed on the SOFTWARE
UPLOAD page.
The software loader card is
installed in the bottom slot of the
GDU 620.
Insert the loader card in the top slot and
cycle power to the GDU.
The software loader card contains
no information.
Repeat the process for making the
software loader card.
Configuration errors are
displayed on power-up,
before the GDU enters
normal mode.
The configuration module has not
been updated.
Update the configuration module.
Vertical GPS deviation is not
displayed on the GDU 620.
For 400W/500W Series units, the
ARINC 429 vertical deviation
labels are not being transmitted.
Enable Labels on the 400W/500W Series
unit ARINC 429 configuration page.
Unable to control the GPS
course when in OBS mode.
The GPS navigator is not correctly
configures as LNAV1/2 or SYS1/2.
Configure the ARINC 429 inputs/outputs
for LNAV1 (SYS1) or LNAV2 (SYS2) based
upon whether the navigator is GPS1 or
GPS2.
Data is not being received
from an ARINC 429 device.
ARINC 429 bus hi and low are
swapped.
Verify wiring.
31-00-00