How do I reset the Zebra ZD420 printer to Factory Defaults?
- Turn OFF the printer.
- While turning ON the printer, press and hold PAUSE + FEED
- Keep holding the PAUSE + FEED until the STATUS indicator is the only indicator lit.
Source: “ZD620 & ZD420 Factory Reset” Zebra, https://supportcommunity.zebra.com/s/article/ZD620-ZD420-Factory-Reset?language=en_US