PR670E / PR670EC FAQs & Troubleshooting PR670E / PR670EC Not your product? Sort by Updated Date Popularity 3 Results 1. 09/19/2017 Tutorial videos on how to use the machine [Video instructions] 2. 07/29/2016 Maintenance (Cleaning the thread paths of the upper threads) [ Video ] 3. 07/29/2016 Maintenance (Cleaning the bobbin case) [ Video ] Instructional videos FAQs & Troubleshooting