HL-L6400DW(T) FAQs & Troubleshooting HL-L6400DW(T) Not your product? Sort by: Updated Date Popularity 3 Results 1. 11/22/2018 Install the optional lower tray 2. 03/18/2016 Install the Tower Tray Unit. 3. 03/18/2016 Install the Mailbox. Consumables / Paper / Accessories FAQs & Troubleshooting