Dell PowerEdge T420 Owner's Manual page 51

Figure 18. Cabling—Optical Drive and Tape Drive
1. connector for power cable extension
2. mini-SAS connector on PERC card
3. ODD2/TBU connector on system board
4. ODD1/TBU connector on system board
5. power connector on x8 backplane
6. SAS tape drive data/power connector
7. optical drive 2 power connector
8. optical drive 2 data connector
9. optical drive 1 power connector
10. optical drive 1 data connector
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