The 929 and 929.xx service toner sensor messages indicate that the printer is having a problem reading the toner cartridge. The problem could be with the toner cartridge or with the toner sensor on the printer. This is especially true if it is a brand-new cartridge and the error started after you installed it.
Power off the printer and install the second toner cartridge.
Power on the printer with the second cartridge installed.
If doing this clears the 929 Toner Sensor error, try printing again.
If the error does not return, the original toner cartridge is likely the cause of the error.
This is especially true if this error message started just after you installed it.
Try moving the encoder wheel forwards and backwards a couple of times to make sure that this wheel is not stuck.
Note: The encoder wheel moves only a little bit each way. DO NOT force the wheel to turn. The wheel must not be able to make a complete revolution. If it does, it is broken.
If this wheel spins freely or does not move at all, you receive a 929 Toner Sensor error on the printer when you try to use this cartridge. In this case, the cartridge must be replaced.
Turn off the printer and remove the toner cartridge.
Look inside the printer in the area below where the cartridge goes. The toner sensor is on the right-hand side. On the back of the toner sensor assembly, you must be able to see a white cable connector.
Make sure that this white cable connector is fully installed into the toner sensor assembly by carefully pushing the connector toward the front of the printer.
Reinstall the toner cartridge.
Close the front lid and power the printer back on.
Contact the point of purchase and explain the situation to them. They may have a replacement policy in place.
If the point of purchase cannot help you, call our Customer Support Center and we will see what we can do to replace the cartridge that is causing the error.
LEGACY ID: SO2947
A 922 Type "Service Fuser" Error (922.04, 922.16, 922.42, etc.) Is Appearing on a Lexmark T640, T642, T644, or an X64xe Series Printer
TSB: (T64x_114): T64x/X64x ? A 902.29 'Service Engine' Error Is Appearing on a Lexmark T640, T642, T644, or an X64x Series Printer