The weakest part of this printer are the plastic gears, especially that one particular gear. It should have been made of steel. I had the same problem. I cut a piece of the bottom plate off to expose the gear. I used a dremel tool with a tiny saw blade attached but I suppose you can also use a multi-tool with a cutting blade. I immediately noticed the gear was cracked straight through to the shaft therefore slipping and making the gear useless. I cleaned the gear and the shaft with alcohol and used epoxy to fix the cracked gear and secure it to the shaft. I put a lot of epoxy on both sides of the gear to make sure it was well bonded. I also dabbed a little on the shaft where the gear seats. I let it dry for 24 hrs and then started using it . It's been working flawlessly since I repaired it and that was 2 years ago.