Epson EPI-4000 User Manual page 119

Using Font Cards
2. Hold the card so that the Epson logo faces up and the arrow
points toward the slot you want to use.
3. Make sure the card is level and then slide it into the slot.
If the printer goes off line and the display reads
CE, the card error message, you inserted the card when the
printer was on line or when the printer's memory
contained data. If you see this message, remove the font
card. Then press ON LINE and return to step 1.
4. Press ON LINE to set the printer on line.
4-4 Options