Innov-is 4000D/4000 FAQs & Troubleshooting Innov-is 4000D/4000 Not your product? Sort by Updated Date Popularity 5 Results 1. 12.12.2018 When thread got tangled. 2. 23.10.2015 Why does the lower thread keep breaking? 3. 20.11.2012 Why does my thread keep jamming? 4. 20.11.2012 Why does the upper thread keep breaking? 5. 20.11.2012 Why does the needle keep breaking? Sewing (Utility Stitches) FAQs & Troubleshooting