Star XB24-250 II User Manual page 12

6 Printer Setup
make sure that the side tabs fit into the grooves on the sides of the cartridge
holder.
While guiding the ribbon between the print head and print head shield,
press down gently on the cartridge until the side tabs snap securely into
place.
Rotate the knob on the cartridge again to take up any slack.
Close the front cover of the printer.
Important!
Printing that is poor quality or too light is almost always due to a ribbon that is
simply worn out or "used up." If you experience problems with print quality,
check the conditio of the ribbon. If the black part looks gray and well-worn,
replace the ribbon with a new one.