Epson LQ-510 User Manual page 22

Assembling the Printer
4. Hold the ribbon cartridge by its handle and push it firmly down
into position, making sure the plastic hooks fit into the slots.
Note: Press lightly on both ends of the cartridge to make sure
the plastic hooks are properly seated.
5. Use a pointed object, such as a ball point pen, to guide the
ribbon between the print head and ribbon guide while you turn
the ribbon-tightening knob to help feed the ribbon into place.
Setting Up the Printer 1-9