NEC Express5800 Series User Manual page 311

IMPORTANT:
Connect the cable to the connector on the lower part.
10.
Loosen the fixed screw on the bracket cover that
corresponds to another PCI slot that is hidden behind
the riser card, and remove the bracket cover.
11.
Install the optional PCI board to another PCI
slot hidden behind the riser card.
12.
Secure the PCI board with a fixed screw.
System Upgrade 8-35