Message Error call service 7980 on Kyocera printers

This error code appears on these printes:

• FS-1116MFP, FS-1118MFP, FS-1016MFP, FS-118MFP, KM-1815, CS-1820...

Cause: 

•  Waste toner tank overflow
• If the bottle is not full then the sensor thinks it is

Solution:

• Clean the sensor
• Replace waste toner tank