MFC-9840CDW FAQs & Troubleshooting MFC-9840CDW Not your product? Sort by: Updated Date Popularity 3 Results 1. 28.01.2013 The keys on the control panel do not respond. 2. 26.08.2011 I heard a beep sound from the UPS (Uninterruptible Power Supply) when I turned on my Brother machine. 3. 23.09.2008 My Brother machine has no power. What can I do? Others FAQs & Troubleshooting