Lexmark 302 - Manual (Page 173)

7. To be sure that you have installed the ribbon cartridge correctly,
check that:
a. The left side of the ribbon cartridge is securely snapped onto
the printer. The right side fits over the ribbon drive post but
does not latch down.
b. There are no twists or folds in the ribbon.
c. The ribbon is not catching on the print head.
d. The ribbon moves when you turn the blue ribbon advance
knob clockwise. If the ribbon does not move, replace the
ribbon cartridge.
B l u e R i b b o n A d v a n c e K n o b
Chapter 3. Replacing Your Ribbon 3-7