Epson Equity 286 PLUS - Manual (Page 188)

3. Holding up the subassembly at an angle, reach under it and
grasp the two main system board power supply cables,
labelled P4 and PS. Each connector has six pin holes and a
large tab on one side, as shown below.
There is one 120pin power supply socket on the right side of
the main system board (toward the back) that holds both of
the power supply connectors, as shown below.
power supply socket
Installing and Removing Disk Drives B-49