Download the most recent ZyXEL
firmware image for the VMG1312-B10A.
With the VMG1312-B10A totally disconnected from everything (including the PSU!), depress and keep held depressed the recessed reset button. With your other hand, connect the power supply. Continue to keep the reset button depressed. Eventually the power LED on the VMG1312-B10A will stop
flashing red and become
solid red. Release the reset button.
Connect a standard Ethernet patch cable to the LAN1 port of the VMG1312-B10A. Connect the other end to a computer whose NIC has been configured with a static IPv4 address in the 192.168.1.[2-254] range . . . use what ever is most convenient, anything
other than the 192.168.1.1 IPv4 address.
Open a web-browser and enter 192.168.1.1 on the address bar. The firmware upgrade page will be shown. Specify the firmware image that you have downloaded and unpacked (above) and initiate the firmware upgrade. Once the upgrade appears to have finished,
don't do anything. Leave the VMG1312-B10A alone for 5 - 10 minutes.Power cycle the device and once it has reinitialised, press and hold the reset button for 5 - 10 seconds. Allow it to reinitialise and then, from the command line, establish a telnet connection using the 192.168.1.1 IPv4 address and the
admin /
1234 credentials. Once logged in, issue the
save_default clean command. Log out, then press and hold the reset button for 5 - 10 seconds.
You now should have a pure vaniila ZyXEL VMG1312-B10A device.