Remove all ofthe toner and drum cartridges from the printer.
the gates from both the toner and drum cartridges to ensure that they
are in a closed position when the cartridges are out from the printer
the Toner and Drum Cartridges are out of the printer, vacuum the
inside of the printer ensuring that there is no toner remaining inside
the cartridges cavity
If the error condition remains even
after vacuuming, replace the toner cartridge in the question; you may
have to replace three color cartridges at the same time (YMC), and the
Black cartridge can be replaced individually.
Check the seal on the Drum Cartridge; in case the seal is broken replace the Drum Cartridge