A 'Toner Sensor' or '929' type numeric error (929.00, 929.01 etc.)

The first time the printer reports this error, power it off. After one or two minutes, power it back on. Did the error message return?

Yes: If the error continues, or returns within a few days, proceed with the steps below.

No: If the printer comes up to the ready state, try printing again. If it prints correctly, the error may have been an isolated incident. Continue normal use of the printer but pay close attention to it over the next few days to see if the error returns.

Should the error continue or return later, try reinstalling the toner cartridge and the photoconductor unit. One or both of these supplies may not be seated inside the printer correctly. Did the error message return?

Yes: If the error continues, or returns within a few days, proceed with the steps below.

No: If the printer comes up to the ready state, try printing again. If it prints correctly, the error may have been an isolated incident. Continue normal use of the printer but pay close attention to it over the next few days to see if the error returns.

Open the front cover. Remove the photoconductor unit and toner cartridge together at the same time.

Note: The photoconductor unit and toner cartridge are known collectively as the print unit.

Once the print unit is installed, remove the toner cartridge and shake it, then reinstall it back to the printer. Ensure that the toner cartridge is fully installed. Then close the front cover and power on the printer. Did the error message return?

Yes: If the error continues or returns later, replace the existing toner cartridge with a new one (if you have an extra cartridge in stock). Install the new toner cartridge and try printing again. If this corrects the issue, the old toner cartridge is defective and should be replaced. If not, continue with the steps below.

No: If the printer comes up to the ready state, try printing again. If it prints correctly, the error may have been an isolated incident. Continue normal printer use but pay close attention to it over the next few days to see if the error returns.

Note: Should the cartridge causing the error be completely or relatively new, check the yield/life rating on that toner cartridge through the EWS ( Embedded Web Server), if printer is connected to the network. If the yield/life rating on the cartridge is 6,000 pages or more, please contact Lexmark Technical Support before purchasing another toner cartridge. A problem may exist with a part on the printer and not with the toner cartridge.

Should the issue continue or return later even after the toner cartridge has been checked or replaced, try replacing the photoconductor unit/kit (if you have an extra one in stock). Did the error message return?

Yes: If the issue continues after you have performed the steps above, a service action may be required to correct the issue. For assistance in setting up service, please contact Lexmark Technical Support or a local authorized service provider.

No: The source of the problem appears to be the photoconductor unit. The photoconductor may be eligible for a warranty replacement; this depends on the age and usage of the photoconductor. Please contact Lexmark Technical Support before purchasing another photoconductor unit.

Note: For detailed instructions on how to replace a photoconductor unit, How to change the photoconductor unit.