How to fix displayed “CHECK TONER” message in 60 seconds

A customer recently asked a Zhono engineer:

Printers, with a Smart-card chip, displayed CHECK TONER” message frequently (fig.1 & fig.2), even following new cartridge replacement.

 check toner.png

fig.1                                                fig.2

Note: All printers described used all-in-one-cartridges and Smart-card chips.  All printers with Smart-card chips can have Check Toner issue.

What is the issue?

Zhono senior engineer describes 3 faults and a solution in 60 seconds. 

The issues of the printer with Smart-card displays "CHEK TONER". 


     <The engineers in Zhono proof reasons of any issues by field testing>   

There are three faults that cause “CHECK TONER” message:

Fault 1. Cartridge contact failure / Solution: repair with adhesive tape

Cartridge fails to engage printer cartridge sensor switch preventing printing and identifying the cartridge.

Solution: Find the cartridge sensor switch(fig.3), cover with a piece of adhesive tape (fig.4), and then install the cartridge. If the printer does not display “CHECK TONER”, it indicates the place shown in (fig.5) has worn and fails to engage the switch.


  fig.3                        fig.4




If the printer still displays “CHECK TONER”, the cartridge sensor switch may be damaged. (Fault 2)

Fault 2  Cartridge sensor switch is damaged / Solution: disassemble and fix

Cartridge sensor switch is damaged: printer cannot identify the cartridge

Solution: Connect the two switch wires directly in a short circuit. The printer will identify  the cartridge as installed.(fig.6)



Fault 3  The main printer board is damaged

Small probability event: If the cartridge can be identified and cartridge sensor switch engages. However, the printer still displays “CHECK TONER”, then the main printer board may be damaged.


① When printer with Smart-card chips reaches toner end, insert a related Smart-card chip and new toner to recover is necessary.

②Improper operation, such as forcibly pushing the cartridge into the printer and breaking the switch, etc., will cause the printer damage.

Post time: Aug-15-2019
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