Dell 1710/n Mono Laser Printer - Manual (Page 58)

What this light sequence means:
The toner cartridge you are using was not designed for your printer.
What you can do:
Install a toner cartridge made for your printer (see Ordering Supplies ).
What this light sequence means:
New code is being programmed into the engine or firmware code flash.
What you can do:
Wait for the message to clear. When the printer has finished programming the
code, it performs a soft reset.