3.10 Replacing the Main Board 
1.  Refer to Remove the Electronics Cover to remove the electronics cover. 
2.  Remove 2 screws (fastened by 5.5 kg±15% kg-cm) on slot-in Wi-Fi/ GPIO interface board (if module installed). 
3.  Remove 2 screws (fastened by 5.5 kg±15% kg-cm) and 2 hexagon screws (fastened by 7.5 kg±15% kg-cm) on interface board. 
4.  Remove 4 screws (fastened by 7.5 kg±15% kg-cm) and all connectors from the main board.   
 
 
       
 
5.  Remove/Replace the main board. 
6.  Reassemble the parts in the reverse procedures.