Epson EQUITY 386/33 PLUS - Manual (Page 103)

5. The power supply socket is on the back of the hard disk
drive, next to the cable you just connected. Pull the power
supply cable through the lower opening in the right side of
the subassembly so it reaches the drive socket easily. Align
the connector with the socket so that the notched comers
line up, as shown below.
notched corners
notched corners
6. Notice that there are two tabs facing downward on one edge
of the mounting plate. These tabs will fit into two slots in
the right side of the subassembly.
tabs
Installing and Removing Drives 5-15