Epson 5000/5500 - Manual (Page 20)

Assembling the Printer
3. Turn the ribbon-tightening knob in the direction of the arrow.
This removes any slack in the ribbon and makes it easier to
install. Next, hold the ribbon cartridge by its handle and push it
firmly down into position; then press on both ends of the
cartridge to make sure the plastic hooks fit into the slots.
4. Use a pointed object, such as a ball point pen, to guide the
ribbon between the print head and ribbon guide. Turn the
ribbon-tightening knob to help feed the ribbon into place.
5. Slide the print head from side to side to make sure it moves
smoothly. Also check that the ribbon is not twisted or creased.
Setting Up the Printer 1-7