Brother laser printers will indicate that you have not installed the toner cartridge properly with an error message on the display panel that reads “Cartridge Position Error.” If you see that error message and you have just installed a new cartridge, you will need to go back and reseat the cartridge before the flashing printer will print satisfactorily again. Other indicators that may appear include a flashing “Toner” light.
Turn the printer on. Open the front cover and take out the Brother drum unit/toner combination. Grab the handle and pull the drum unit/toner combination out horizontally. Don’t touch the electrodes on the inner sides of the printer because static electricity can damage the printer.
Place the drum unit/toner combination on a newspaper--toner can spill and make a mess. Push down on the green lock lever and remove the toner cartridge from the drum unit.
Hold the cartridge level and rock it from side-to-side to distribute toner.
Put the toner back into the drum unit. You will hear a click when it is reset correctly. You must hear the click and see the lock lever rise automatically or it won’t be reset.
Clean the corona wire inside the drum unit by sliding the green tab from left to right. Make sure the green tab is reset back at its original position—all the way over to the right (if the corona wire is at the back when you are looking at the drum).
Put the drum unit/toner combination back into the printer and close the cover.