Epson 386/25 - Manual (Page 122)

5. Grip the card firmly by the top comers and position it at the
top of the slot, as shown below. Make sure the connector
pins point down and the component side faces the power
supply inside the computer.
power Supply
6. Insert the card into the slot, guiding it straight down. Once
the connector pins reach the connector slot, push the card
downward firmly (but carefully) to insert it fully. You should
feel the card fit into place.
If the card does not go in smoothly, do not force it; pull it all
the way
out and try again, keeping it straight as you insert it.
Examine the card to verify that it is fully seated in the slot
along the length of the connector.
5-14 Installing and Removing Options