Dell 1710/n Mono Laser Printer - Manual (Page 57)

What this light sequence means:
The imaging drum is full and needs replacing. The printer will not print any
more pages until the imaging drum is replaced.
What you can do:
Replace the imaging drum. For more information, see Replacing the Imaging
Drum .
What this light sequence means:
The toner cartridge is not installed, or the printer detects a toner cartridge
error.
What you can do:
If the toner cartridge is not installed, install it.
If the toner cartridge is installed, remove it and install a new toner
cartridge (see
Replacing the Toner Cartridge ).