Dell PowerEdge R740xd Installation And Service Manual page 181

Figure 139. Cable routing – 12 x 3.5 inch drive backplane with 4 x 3.5 mid drive tray and 2 x 3.5 rear drive cage
1 backplane
3 backplane power cable
5 SAS cable
7 system board
9 SAS cable
2 backplane signal cable
4 SAS cable
6 mid drive backplane
8 rear drive backplane
Installing and removing system components 181