MFC-9840CDW FAQs & Troubleshooting MFC-9840CDW Not your product? Sort by: Updated Date Popularity 3 Results 1. 10/06/2015 How do I install the Optional Tray Unit? 2. 30/07/2007 What kind of memory can I use? 3. 12/07/2007 How do I install additional memory? More FAQs Consumables / Paper / Accessories FAQs & Troubleshooting