Overview

How to identify or differentiate the old and new dot matrix cartridge
How to replace the ribbon on a dot matrix printer

Ribbon cartridge identification

Bottom view	Top view
Ribbon Advance (encircled red in this image) Note: External dimensions on the old and new style are slightly larger but the internal dimensions are identical. Easier to fit onto the printer gear.

Ribbon cartridge replacement procedure

Step	Action	Image
1	Release the latches on the upper cover and move the cover to an open position.
2	Lift the cover straight up to remove it from the printer.
3	Pinch the tabs inward to release the cartridge.
4	Lift up the cartridge to remove it.
5	Insert the new cartridge, with the print head side slightly ahead of the body.
6	Push the cartridge into position with two fingers. Do not press on the release tabs.
7	If the cartridge does not lock into place, rotate position knob in the direction shown by arrow (shown on the image) slightly and re-try.
8	Once the cartridge is in position, install the upper cover.	...