MFC-9420CN FAQs & Troubleshooting MFC-9420CN Not your product? Sort by: Updated Date Popularity 2 Results 1. 01/29/2014 I'm using Voice Over Internet Protocol (VoIP) and am having problems receiving faxes. 2. 05/10/2013 Why doesn't the machine answer when receiving a call? Fax FAQs & Troubleshooting