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GNS 400W Series Maintenance Manual
Page 5-11
190-00356-05
Rev. A
5.4.4 Main Chassis Top Cavity (Figure 5-7)
WAAS GPS Chassis (all units)
Removal
1.
Remove one screw (1) attaching WAAS GPS Module (2) to Main Board (3). Remove
three screws (4) attaching WAAS GPS Module to Main Chassis (5).
2.
Lift WAAS GPS Module off of Main Board Connector and out of the Main Chassis (5).
Replacement
1.
Place replacement WAAS GPS Module on Main Board Connector.
2.
Install one screw (1) securing WAAS GPS Module to Main Board.
3.
Install three screws (4) attaching WAAS GPS Module to Main Chassis.
Main Board (all units)
The Main Board is not a serviceable item, but can be removed to replace the Memory Battery.
Removal
1.
Remove CDU Assembly.
2.
Remove WAAS GPS Module from Main Board (section above).
3.
Remove GPS Ribbon Cable that is attached to the Main Board.
4.
Remove two screws (6) attaching the 78-pin connector to Main Chassis (5).
5.
Remove five screws (7) attaching Main Board to Main Chassis.
6.
Remove Main Board (3) but leave Mylar Insulator (8).
Replacement
1.
Place Main Board in Main Chassis Cavity.
2.
Attach with five screws (7).
3.
Attach the 78-pin connector to Main Chassis (5) using two screws (6).
4.
Attach WAAS GPS Module to Main Board.
5.
Connect GPS Ribbon Cable to the Main Board (3).
6.
Install CDU Assembly.