Troubleshooting a 111.21 service printhead error

Issue description

When printing, the printer posts a 111.21 Printhead Error upon boot up or after re-inserting the toner cartridge and imaging unit inside the printer.

This may be caused by the printhead not getting the required power to start due to faulty signal transmission caused by improper insertion of the toner cartridge and imaging unit.

Solution

1. Open the printer's top cover.



2. Remove the toner cartridge and then the imaging unit.



3. Reinsert the toner cartridge and the imaging unit. Make sure that everything is seated properly.



4. Restart the printer.

If the error returns upon restarting, repeat the procedure.