Brother TN-350 Toner – Shows Replace Toner?

If you have just replaced the toner and the machine is still telling you to replace the toner. It quite likely the toner sensor flag on the side of the toner has not been “tripped” to recognize another toner has been replaced.

There is also an optical sensor built on both sides of the toner, this prompts the user when toner supply is really low. The sensor monitors toner supply levels by shining a light beam across a toner cartridge window. If no toner is detected, the ‘low toner’ light consequently blinks. The amount of toner filling the chamber is employed to block the light beam delivered by the sensor; thus, the printer continues to operate. But once toner is depleted, the light beam connects, completes the circuit and the ‘low toner’ prompt appears. In the picture the cartridge window is the clear plastic round window.

If the cause of the stoppage is the optical sensor, placing a black electrical tape right across the cartridge window will solve the problem.

Another feature of the Brother TN 350 toner cartridge is the reset gear that accurately monitors the number of pages printed by the printer. This counting device is activated depending on the number of revolutions made by the cartridge developer roller. Once the rated capacity is reached, the device turns off the printer automatically.

Adjusting the reset gear would resolve the issue. Adjust the reset gear flag to its starting position.

 

Left: The Sensor flag                   Right: Sensor flag is now ready

In the above photo you can clearly see the toner flag sensor is now ready facing forward. Have a look at the old toner cartridge; the old toner will have the flag in its “tripped” position. As the toner is placed into the printer the sensor flag is push back. Your new toner cartridge if not in this position the printer will go into the replace toner error mode. You gently move the flag forward, pushing against the small cogs/gear mechanisms. Once done this flag now resets the printer when the cartridge is installed.