Epson 486SX - Manual (Page 114)

3. Unpack the option card. When you handle it, be careful not
to touch any of the components on the circuit board or the
gold-edged connectors. If you need to set it down before
you install it, place it gently on top of its original packing
material with the component side facing up. Keep the
packing materials in case you remove the card later.
Adjust any switches or jumpers on it, if necessary. (Check
the option card instructions.)
4. Grip the card firmly by the top corners and make sure the
connectors point down, as shown below.
5. Insert the card into the slot, guiding it straight down. Once
the connectors enter the 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.
Installing
and Removing Options 6-11