Instruction Manual

Instructions for Continued Airworthiness 190-01190-11 Rev. 1
for G500H in Robinson R44 Series Rotorcraft Page 11 of 20
2.6.2 G500H Alerts
The G500H will display a number of alerts on the GDU 620 MFD. These are listed in the following table.
Table 2-2. GDU 620 Alert Troubleshooting Guide
Alert Text Cause Solution
<LRU> SERVICE Specific LRU should be serviced,
where <LRU> denotes specific
LRU.
Return indicated LRU to Garmin for
service.
AHRS1 GPS – AHRS 1 using
backup GPS source.
AHRS is using the backup GPS
information
Verify GPS1 power and check the wiring
AHRS1 GPS - AHRS is not
receiving any GPS information
AHRS is not receiving any GPS
information.
Verify GPS power and check the wiring
AHRS1 GPS – AHRS 1
operating in exclusively in no-
GPS mode.
AHRS is not receiving any GPS
information.
Ensure that at least one GPS has
acquired a valid position.
If GDU 620 does not have a valid
position, verify wiring between GDU and
GPS receiver, and configuration of GDU
620 and GPS receiver.
If GDU has a valid GPS position, verify
wiring between GDU and GRS. Also
verify time mark wiring.
AHRS1 GPS – AHRS 1 not
receiving backup GPS
information.
AHRS is not receiving GPS
information from GPS2.
Verify GPS2 power and check the wiring
AHRS1 SRVC AHRS magnetic field model should
be updated. Appears on ground
only.
Update GRS 77H IGRF model (current
model is with aviation database).
AHRS1 TAS AHRS is not receiving true airspeed
from ADC.
GDC not powered up. Close ADC C/B.
GDC not receiving input from GTP 59
OAT probe. Verify wiring is correct.
ARINC 429 connection from GDC 74H to
GRS 77H is not working. Verify wiring is
correct.
AUD NOT AVAIL Audio system not available. Contact Garmin Technical Support.
AUD SYS FAIL Audio system failure Contact Garmin Technical Support.
CAL LOST Registry reports that it has lost
calibration data.
Contact Garmin Technical Support.
CNFG MISMATCH –
GDU 1-2 airframe
configurations disagree.
(Applicable only to dual GDU
installations)
GDU in normal mode has
received updated crossfill tags
for configuration registry entries.
Restart both GDUs in configuration mode
to automatically synchronize settings.
CNFG MODULE The configuration module is
inoperative.
Verify wiring to configuration module
Replace configuration module
DATA LOST Pilot stored data was lost. Recheck data and settings.