Dell PowerVault NX3100 Hardware Owner's Manual page 119

CAUTION:
To prevent damage to the drives and backplane, you must remove the
hard drives from the system before removing the backplane.
CAUTION:
You must note the number of each hard drive and temporarily label
them before removal so that you can replace them in the same locations.
4 Remove all hard drives. See "Removing a Hot-Swap Hard Drive" on
page 70.
5 Disconnect the power cable from the end of the SAS backplane.
6 Disconnect the SAS data cables from the backplane.
7 Disconnect the optical-drive cable, USB cable, internal hard-drive cables,
and the control-panel cable.
CAUTION:
Handle the cables gently to prevent damage.
8 While pressing the two blue latches toward each other, lift the backplane
upward. See Figure 3-24.
9 When the backplane cannot slide upward any farther, pull the backplane
toward the back of the system to remove it from the retention hooks.
10 Lift the board out of the system, being careful to avoid damaging
components on the face of the board.
11 Place the SAS backplane face down on a work surface.
Installing System Components
119