Dell Alienware Area 51 R2 (Late 2014) - Manual (Page 55)

2 Disconnect all cables from the connectors on the I/O board.
NOTE: Note the routing of all cables as you remove them so that you
can reroute them correctly after you replace the I/O board.
1 cables 2 connector
3 I/O board
3 Remove the screws that secure the I/O board to the chassis.
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