Unplug the main machine power cord before you do the following procedure.
Remove the controller cover [A] ( x 3).
Pull out the controller board [B] ( x 5).
Remove the slot cover [A] ( x 1).
Attach the Gigabit Ethernet controller [A] into the slot [B] ( x 2).
Reassemble the machine.
Check the operation of the Gigabit Ethernet