Epson EQUITY 386/33 PLUS - Manual (Page 112)

7. Align the connector with the socket so that the row in the
connector with the blocked hole lines up with the row in
the socket with the missing pin, as shown below. Make sure
the holes fit over all the pins and then push in the connector.
missing pin
Caution
If you do not correctly align the holes with the pins, you
could severely damage your hard disk drive when you
push in the connector.
8. Looking at the subassembly, locate one of the power supply
cables that lead from the power supply (behind the
horizontal drive bays). The cables are labelled P1, P2, and
P3; you can use any one.
5-24 Installing and Removing Drives