190-01007-01
GTN 725/750 Maintenance Manual
Rev. 5
Page 5-3
5.2 GTN Removal with Damaged Jackscrew
In the event the unit retention jackscrew becomes stripped while the GTN is in the installed position,
remove the GTN from the rack by following this procedure.
1. Pull the GTN main, COM, and NAV circuit breakers. Refer to individual aircraft installation
documentation to determine circuit breaker locations.
2. Gain access to the unit retention cam head. Refer to figure 5-2 for details.
3. Remove the countersunk screw connecting the cam head to the retention arm.
4. Remove the cam head.
CAUTION
Removing the cam head screw will allow the retention arm linkage to swing freely inside
the bottom cover. While this will not damage the GTN, attempting to realign the retention
linkage components may cause damage to the GTN 750 NAV circuit board. As such, do not
attempt to replace the cam head on the bottom cover once the GTN 750 is removed from
the rack. Instead replace the entire bottom cover.
5. Remove the GTN from the rack.
6. Remove and replace the bottom cover. Refer to section 5.6 for details.
Figure 5-2 Cam Head Removal
