Dell DSS 2500 Owner's Manual page 130

CAUTION: To prevent damage to the hard drives and hard drive backplane, you must remove the hard drives from the system
before removing the hard drive backplane.
CAUTION: You must note the number of each hard drive and temporarily label them before removal so that you can reinstall them
in their original locations.
1 Follow the safety guidelines listed in the Safety instructions section.
2 Follow the procedure listed in the Before working inside your system section.
3 Remove all hard drives.
Steps
1 Disconnect the left control panel, SAS/SATA data cable(s), and power cables from the hard-drive backplane.
2 Press the hard drive backplane release tabs to disengage the backplane from the chassis.
3 Push the hard drive backplane away from the system until the securing hooks on the system chassis are free from the slots on the
hard drive backplane.
4 Lift the backplane partially away from the system and disconnect the control panel cable, USB cable, and backplane signal cable.
5 Lift the backplane away from the system.
Figure 67. Removing the SAS/SATA backplane
1 release tab (2)
3 backplane signal cable
5 SAS cable B1/A1
7 control panel
9 hard drive backplane
130 Installing and removing system components
2 left control panel flex cable
4 backplane power cable
6 USB cable
8 backplane power cable
10 hard drive backplane connector (12)