Use the following steps to perform a Factory Reset:

1. Turn the printer off.
2. Hold down the Go button on the front panel of the printer.
3. Turn the printer back on while holding the button down.
4. When the TONER light (LED)  is lit by itself, let go of the button.
5. Push the Go button again and hold until the PAPER light (LED) is lit by itself and release the button.

This has performed a factory reset on the printer.