How do I find and resolve Toner Sensor Errors?
If your printer displays a toner sensor error please check the following:
Please carry out the following instructions if you receive one of the following error codes:
540 Toner Sensor Error, Colour: Yellow
541 Toner Sensor Error, Colour: Magenta
542 Toner Sensor Error, Colour: Cyan
543 Toner Sensor Error, Colour: Black
The printer contains four image drums; cyan, magenta, yellow and black*.
*WT models contain four image drums: cyan, yellow, magenta and white.
How do I find the Toner Sensors?
Press the cover release and open the top cover fully and note the positions of the four cartridges:
NB. if you have a WT model the position will be different.
There are two sensors for each toner: one on the drum (TS1) and one on the machine (TS2).
TS1: The toner sensor is located on the right hand side of the drum
TS2: The Toner sensor on the machine can be found on the right hand side panel of the machine on the inside (see image below).
The sensor is enclosed in an oval shaped hole, this works in conjunction with the toner sensor located on the right hand side of the drum.
Toner sensor (view from above) Toner sensor on the machine (side view)
Toner Sensor Errors
A toner sensor error is displayed when the machine is no longer able to detect the toner cartridge / drum unit, or is no longer able to determine how much toner is left in the units.
How to clear the Toner Sensor Errors
If your printer displays a toner sensor error please power off the printer and check the following:
Check that all the blue toner levers are pushed firmly towards the back of the machine
Check if the sensors need to be cleaned. The sensor is located behind a plastic cover on the side of the drum (see below). Remove the plastic cover and give the silver arm a clean with something small and soft (lint free), any toner that has built up on the sensor will be a very fine powder and should be easy to remove.
Sensor with cover on Sensor with cover off
Check if the sensor lever on TS1 has been pushed up. Once you have cleaned the arm, check that the sensor lever has been pushed up (see Correct Position below).
Correct Position Incorrect Position
If it is incorrect it can sometimes result in the blanking disc not being pulled out of the way, this results in the sensor on the machine not picking up the sensor on the drum. Pushing the disc up will resolve the problem. The disc will not fall back down again, providing that the blue Toner Lever is pushed firmly to the back of the machine.
After all these checks are completed place the cover back on the side of the drum. It should go back on the same way it came off. If you are unable to fit the plastic cover on the drum, you can leave it off as it will not stop the drum from printing.
Install the drum and toner in the machine and switch on, if you still have an error message please contact your local OKI Support Representative for further assistance.