TX2550 M4 Upgrade and Maintenance Manual 237
Hard disk drive (HDD) / solid state drive (SSD)
Figure 152: Installing the second 3.5-inch HDD SAS backplane (B)
Ê Ensure that the SAS backplane is properly seated into the bottom rim and 
side guide (see arrows).
Ê Ensure that the upper edge of the SAS backplane is flush with the HDD bay 
divider wall (see dashed line).