Dell Precision 490 - Manual (Page 57)

7. Disconnect the data cable from the back of the hard drive and from the connector on the system board.
If it is connected to a card and you will not be reinstalling the drive, route the data cable to the side.
8. Slide the sliding-plate lever to the right to release the shoulder screw and slide the drive out of the FlexBay.
1 sliding-plate lever 4 power supply
2 SATA data cable 5 SATA_2 connector
3 power cable 6 optional SATA hard drive in FlexBay
1 SAS data cable 4 SAS connector
2 power cable 5 optional SAS controller card
3 power supply 6 optional SAS hard drive in FlexBay