Epson EQUITY 3865X/20 PLUS - Manual (Page 108)

Removing the Subassembly
In order to install disk drives or access the jumpers or math
coprocessor socket on your computer’s main system board, you
need to remove the subassembly. The subassembly is the large
metal casing that holds the horizontal drive bays and the power
supply, as shown below.
Follow these steps to remove the subassembly:
1. Turn the computer so the front panel is facing you.
Accessing Internal Components
5-5