Epson EQUITY 3865X/20 PLUS - Manual (Page 111)

6. Still holding up the subassembly, reach further back
underneath it and disconnect the two power supply cables
connected to the back right side of the main system board,
as shown below. Pull each of the connectors straight up. Do
not pull on the cables.
power supply cables
7. Lift the entire subassembly out of the computer and carefully
place it on your work surface.
Replacing the Subassembly
Follow the steps below to replace the subassembly inside your
computer:
1. Notice that there are four mounting slots on the back of the
subassembly: two in the upper comers and two in the lower
comers.
5-8 Accessing Internal Components