The encoder strip tells Eddie where it is horizontally as it is printing. If the left side mount breaks or falls off due to contact with cookies or hands, this video explains how to fix it. To purchase replacement parts, search for these parts.
If you still have trouble after installing the encoder mount, the encoder strip may have gotten grease on it, or it could be out of place behind the cartridge carrier. Take a look at these two articles/videos.
Article ID: 092823