The Brother machine has separate consumables for the toner cartridge and the drum unit. Verify you replace only the Toner Cartridge and not the drum unit. If you want to know their difference, refer to "What is the difference between the toner cartridge and the drum unit?"

Follow the procedure below to replace toner cartridges.

1. Press the cover release button and then open the front cover of the printer.
   
2. Pull out the drum unit assembly (drum unit with toner cartridge).
   
   
   
   
   • We recommend that you place the drum unit and toner cartridge assembly on a piece of disposable paper or cloth in case you accidentally spill or scatter toner.
   • To prevent damage to the printer from static electricity, do not touch the electrodes shown below.
   
3. Push down the blue lock lever and take the toner cartridge out of the drum unit.
   
   
   
   
   • Handle the toner cartridge carefully. If toner scatters on your hands or clothes, immediately wipe or wash it off with cold water.
   • Be sure to seal up the toner cartridge tightly so that toner powder does not spill out of the cartridge.
   • Discard the used toner cartridge according to local regulations, keeping it separate from domestic waste. If you have questions, call your local waste disposal office.
4. Unpack the new toner cartridge. Hold the cartridge level with both hands and gently rock it from side to side five or six times to spread the toner evenly inside the cartridge.
   
   
   
   
   • Wait to unpack the toner cartridge until immediately before you put it in the printer. If toner cartridges are left unpacked for a long time the toner life will be shortened.
   • If an unpacked drum unit is put in direct sunlight or room light, the unit may be damaged.
5. Pull off the protective cover.
   
   
   
   

   Put the toner cartridge in the drum unit immediately after you have removed the protective cover. Do not touch the shaded parts shown below to prevent any degradation to the print quality.
   

   
6. Put the new toner cartridge firmly into the drum unit you hear it lock into place. If you put it improperly, the lock lever will lift automatically.
   
   
   
   

   Make sure you fit the toner cartridge properly or it may separate from the drum unit.
7. Clean the primary corona wire inside the drum unit by gently sliding the blue tab from right to left and left to right several times. Return the tab to the home position(s) before you put the drum unit back in the printer. If you do not, printed pages may have a vertical stripe.
   
   
8. Put the drum unit assembly back in the printer. Close the front cover of the printer.