MFC-7450 FAQs & Troubleshooting MFC-7450 Not your product? Sort by: Updated Date Popularity 2 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. Others FAQs & Troubleshooting