Dell Precision 350 - Manual (Page 27)

6. Connect a power cable to the drive.
7. Locate the extra connector on the drive cable that is attached to your first hard drive and attach the connector to the second hard drive.
Your computer uses cable-select drive cables. This means that the device connected to the end connector of the drive cable is the master device and
the device connected to the middle connector is the slave device. Be sure that the jumper setting on the new device is set for "cable select" (see the
documentation that came with the drive for information).
8. Close the computer cover .
9. Connect your computer and devices to electrical outlets, and turn them on.
10. See the documentation that came with the drive for instructions on installing any software required for drive operation.
1 rail tabs (2)
2 second hard drive in upper
bay
3 first hard drive in lower
bay
4 hard drive bay
NOTICE: Match the colored strip on the cable with pin 1 on the drive.
1 power cable
2 second hard-drive cable
(secondary drive)
3 first hard-drive cable
(primary boot drive)
NOTICE: To connect a network cable, first plug the cable into the network wall jack and then plug it into the computer.