PR670E FAQs & Troubleshooting PR670E Not your product? Sort by Updated Date Popularity 3 Results 1. 19/09/2017 Tutorial videos on how to use the machine [Video instructions] 2. 29/07/2016 Maintenance (Cleaning the thread paths of the upper threads) [ Video ] 3. 29/07/2016 Maintenance (Cleaning the bobbin case) [ Video ] Maintenance FAQs & Troubleshooting