PC-8500/8500D FAQs & Troubleshooting PC-8500/8500D Not your product? Sort by Updated Date Popularity 5 Results 1. 12/12/2018 When thread got tangled. 2. 10/23/2015 Why does the lower thread keep breaking? 3. 11/20/2012 Why does my thread keep jamming? 4. 11/20/2012 Why does the upper thread keep breaking? 5. 11/20/2012 Why does the needle keep breaking? Sewing (Utility Stitches) FAQs & Troubleshooting