NEC Express5800 User Manual page 330

9-40 Upgrading Your Server
6.
Make the component side of the board face the bottom of the server, put the rear panel of
the board on the frame spring securely, and push the board fully so that the board
connection port is certainly connected to the slot.
For a long-sized board, align the board with the groove of the guide rail on the front of the
server and then connect the board to the slot.
IMPORTANT: If the board cannot be installed well, remove the board
once and then install it again. Note that adding an excess force to the
board may cause it to be damaged.
PCI guide rail