DCP-9040CN FAQs & Troubleshooting DCP-9040CN Not your product? Sort by: Updated Date Popularity 4 Results 1. 01/29/2014 How do I clean the drum unit? 2. 08/22/2007 How do I clean the laser scanner windows? 3. 07/10/2007 How do I clean the scanner to improve the copy quality? 4. 03/29/2007 How do I clean the corona wires? Cleaning FAQs & Troubleshooting