Hi there! Yes, flashing Zyxel NBG6817 to LEDE is not as straightforward as e.g. R7800. But still, hardbricking the NBG6817 is very difficult, you should be able to recover your device by TFTP method:
- Download latest stock firmware, rename to
- On your Windows PC, install TFTP of your choice. My favorite is the Windows built-in one. Install by using
Win + R->
Windows Features(left side panel) ->
- Open up a command-line where
ras.binis located (
Shift + Right-Click->
Open Command-line here)
- Manually set your Windows PC to IP address
- Turn off the Zyxel, wait 30 seconds.
- Press and hold WPS button, turn on your device, keep WPS pushed.
tftp -i 192.168.1.1 put ras.bininto your commandline.
You might need a few runs or try your luck with other TFTP programs. Your device will give you LED signals in order to indicate, when it's ready to accept TFTP image. Unfortunately, I don't remember it in detail anymore. Also, make sure to disable Windows Firewall, as it may eventually get in your way. Good luck and please report back.
Edit: after you have recovered your device, I suggest flashing latest stock firmware 2 times via GUI. This will make sure both dual boot partitions are populated with a working firmware.