Brother HL-5240 - Reset Drum
After changing a DR3100 drum unit in a Brother HL-5240, the printer’s page count needs to be reset. This will turn off the drum warning light on the printer.
Simply open the front cover, and hold the “GO” button until all four LED’s are lit. Release the “GO” button and close the front cover.
Youtube Video: Drum Reset
Brother HL-5240 - Change Toner Cartridge
Youtube Video: Change Toner Cartridge