If you have just replaced the toner cartridge and the machine is still telling you to replace the printer ink, it is quite likely that the toner sensor flag on the side of the toner has not been “tripped” to recognize another toner has been replaced.
Check to ensure that the dial on the left side of the print cartridge is in the position. If not, turn the dial counter clockwise until it matches the position. If not, turn the dial counter-clockwise until it matches the dial position. It is imperative that this dial be locked into position to ensure that the printer detects that a new cartridge has been installed and resets the “REPLACE TONER” mode. Check to make sure that the printer is powered up during the entire process. Changing the printer ink with the printer powered off will not reset the “REPLACE TONER” mode. In the event that the printer is powered off when the printer ink cartridges are installed, you will need to remove the cartridge and repeat step one before reinstalling the cartridge. Put the new toner cartridge firmly into the drum unit you hear and feel it lock into place. If installed successfully, the green lock lever will lift automatically.
People who use Brother Printers, which use Brother TN420 or TN450 toner cartridges, might encounter toner error messages such as “Toner Low”, “Replace Toner” or “Toner Life End”. As the screen shows the cartridge you are using is empty or not recognized, you think you have to replace a new toner cartridge, or you cannot continue printing. But after installing a new cartridge, the problem still exists, and you will find that this happens with both OEM and compatible laser toner cartridges. It doesn’t mean the cartridge you bought is damaged, the reason is the cartridge didn’t reset properly, so the printer couldn’t recognize it as new one. Don’t worry, it is easy to reset.
For Brother HL Series:
1. Turn the printers power off.
2. Open the front cover to the toner/drum section of the printer.
3. Press and hold the “Go” button while turning on power to the printer.
4. Release the “Go” button after “Toner, Drum, and Error” LEDs turn on with the “Ready” LED turn off. All LEDs will now be OFF.
5. Press the “Go” button 2 times – The “Toner, Drum, and Error” LEDs will turn ON.
6. Press the “Go” button 6 times for a TN420 or Press the “Go” button 7 times for TN450.
7. Close the front cover after “Error” LED starts to flash.
8. The reset procedure has been completed.