190-02207-A2
GPS 175/GNX 375/GNC 355 Part 23 AML STC Maintenance Manual
Rev. 3
Page 6-2
6.1 GPS 175
6.1.1 GPS 175 Removal
1. Locate and open the GPS 175 circuit breaker.
2. Locate the unit retention mechanism access hole at the top-right corner of the unit face.
3. Insert a 3/32” hex tool into the access hole and turn the fastener counterclockwise until the unit is
forced out about 3/8” and the hex drive tool stops completely.
4. Slide the GPS 175 out of the rack.
6.1.2 GPS 175 Re-installation
NOTE
It may be necessary to insert the hex drive tool into the access hole and turn the tool
counterclockwise until it completely stops in order to ensure correct position of the
retention mechanism prior to placing the unit in the rack. To ensure connectors mate
properly, center the unit in the rack.
CAUTION
Be sure not to overtighten the unit into the rack. The application of hex drive tool torque
exceeding 15 in-lbf can damage the locking mechanism.
1. Ensure that the GPS 175 circuit breaker is open.
2. Slide the GPS 175 straight back into the rack until it stops about 3/8” short of the fully seated
position.
3. Insert a 3/32” hex drive into the unit retention mechanism access hole at the top right of the unit.
4. Turn the tool clockwise while pressing on the left side of the bezel until the unit is firmly seated in
the rack.
5. Once the GPS 175 is re-installed, verify that the unit power-up self-test sequence is successfully
complete and no failure messages or configuration error messages are annunciated. Section 6.4
outlines the power-up self-test sequence.