Garmin GTN 635 Installation Manual page 123

6.12.2.3 Two GTNs/Two SN3308s
1. Remove power from GTN #2.
2. Cycle power to GTN #1 and acknowledge the prompts until it gets to the Instrument Panel Self
Test page.
3. Select GPS1 as the navigation source by pressing the NAV key on the SN3308. Verify that GPS1
is displayed on the SN3308.
4. Ensure that the SN3308 is receiving valid heading.
The Vertical Deviation Indication will not be displayed unless the SN3308 is receiving
valid heading.
5. While GTN #1 is displaying the self test page, verify that the SN3308 is displaying the following
data from GPS1.
Course Deviation:
Vertical Deviation:
Active Waypoint:
6. On GTN #1 verify that an OBS value is displayed (and not dashed out).
7. Acknowledge the self test on GTN #1 by touching the ‗Continue' key.
8. Select VLOC on GTN #1 and verify that the SN3308 displays NAV 1 or NAV 2 (depending on
which navigation source the GTN is).
9. Using a VOR test set verify that the CDI deviation on the SN3308 is displayed correctly.
10. Remove power from GTN #1 and apply power to GTN #2 and acknowledge the prompts until it
gets to the Instrument Panel Self Test page
11. Select GPS2 by pressing the NAV key on the SN3308.
12. Repeat steps 4-9 with GTN #2.
13. Perform the same procedure for the second SN3308. Ensure that SN3308 #2 is receiving valid
heading by ensuring the vertical deviation indication is being displayed.
14. Repeat steps 5-12 for SN3308 #2.
GTN 625/635/650 TSO Installation Manual
190-01004-02
NOTE
Half-scale left deviation, TO indication, flag pulled
Half-scale up deviation, flag pulled
GARMN
Page 6-43
Rev. C