Garmin G900X Installation And Maintenance Manual page 289

5. When the CALIBRATE field is blinking, press the ENT key to begin the procedure, and have a
stopwatch ready to begin recording the elapsed time.
Ensure that the "time equals zero" moment corresponds with the moment PFD #1 first
displays the blinking "TEST COMPLETE?" message.
6. The operator should carry out the actions called for in the prepared test sequence.
Ensure that all actions are carried out in the order and at the precise elapsed time as
specified in the prepared test sequence.
7. When the operator has completed the actions specified in the test sequence, press the ENT key to
indicate that the process is complete. When this is done, the TEST COMPLETE field stops
blinking. PFD #1 informs the operator if the installation has passed or failed the magnetometer
interference test. If the test passes, no further action is required for this test.
If the test fails, the installation should be considered unreliable until the source of magnetic interference is
identified and remedied. When the magnetometer interference test fails, record the three magnetometer
maximum deviation values and their corresponding timestamps. Any maximum deviation value greater
than 5.0 milliGauss indicates a problem that must be resolved. Compare the corresponding timestamps
with the prepared test sequence to identify which action produced the problem. Contact Garmin for
assistance in resolving the problem.
Two common reasons for a failed magnetometer interference test are: 1) new equipment
is installed in close proximity to the GMU 44 magnetometer, and 2) an existing or new
electronic device has become grounded through the aircraft structure instead of via the
proper ground wire in a twisted shielded pair.
8. Press the ENT key on PFD #1 to conclude this procedure.
G900X/G950 Installation and Maintenance Manual – Software, Configuration, and Calibration
190-00719-00
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Revision D