Epson EL 486UC - Manual (Page 90)

If you are installing a hard disk drive in the upper
horizontal bay, make sure you use the proper hard disk
drive ribbon cable and connect the ribbon cable to the hard
disk drive connector. Also, if this is the second hard disk
drive in your system, make sure you set the jumpers on
both hard disk drives to indicate which is the master and
which is the slave drive. See the documentation that came
with your hard disk drive for instructions.
3. Locate one of the power supply cables that lead from the
power supply. (They have multi-colored wires and a plastic
connector on the end.)
4. Align the notched corners of the power supply cable
connector with the notched corners of the drive’s power
supply connector (such as the one shown below). Make
sure the holes fit over all the pins and then push in the
connector.
Caution
If you do not align the cable connectors correctly, you could
severely damage your drive when you push them in.
Installing and Removing Drives 4-17