Flashed the wrong AX68U Firmware on your AX86U Mesh Router and Can't Reset? This is how I fixed it

[viTRifY13]

Long story short, I was tired and totally missed the fact that I downloaded merlin's firmware for an AX68U router and not an AX86U router. Once it was flashed, I couldn't access the mesh or reset the device! I thought I was stuck and bricked the mesh router. Here's how I fixed it as I'm sure someone else is bound to do the same thing / be in the same situation in the future.

1. First thing first was to get the router back onto my mesh network as I couldn't log into it or reset it. To do that, you need to ensure your ethernet backhaul connection is on port #1 (my usual backhaul connection is on the 2.5G port, but the AX68U firmware doesn't recognize that port).
2. Once you have the router recognized in your mesh network, it'll show "offline" in your nodes like this (attic):
   
   
3. Click on the device and obtain the IP address
   
   
4. Navigate to Administration -> System -> Service and ensure Enable SSH is "LAN Only" and make note of your SSH Port (default is 22, but it's a good idea to change it). Save / reboot
5. Open up WinSCP and log into your mesh router (the broken one) over the SCP protocol, should look like this:
   
   
6. Enter in your router username and password (it's not the default admin / admin, but your password to get into your main router - 192.168.50.1)
7. Copy the correct firmware file (e.g. RT-AX86U_3004_388.6_2_pureubi.w) over to the /tmp/home/root/ folder. Can drag / drop, should look like this:
   
   
8. Open putty (ctrl+p in WinSCP), retype the main router password you used to log into WinSCP with
9. Copy the command "hnd-write RT-AX86U_3004_388.6_2_pureubi.w" as shown below and hit enter. Obviously change the filename in the command if you're flashing a newer / different firmware version
   
   
   
   
10. Once it's completed, type "reboot" and click enter (this will end your putty / winscp connections)
11. Once rebooted, go plug that ethernet backhaul back into the 2.5g port
12. Click "Reboot" at the top of your 192.168.50.1 main router page to reboot all devices in the network
13. Pay extra attention next time you do a firmware update!

 

[Tech9]

You did two mistakes, actually - wrong firmware file download (1) and flash method with no model verification (2).

If you flash firmware in a normal and expected way in GUI this error will never happen. The wrong firmware will be rejected.

 

[viTRifY13]

And this is the proof that mesh router is back to being an RT-AX86U =)

 

[viTRifY13]

You did two mistakes, actually - wrong firmware file download (1) and flash method with no model verification (2).

If you flash firmware in a normal and expected way in GUI this error will never happen. The wrong firmware will be rejected.

Yup...

But I can't remotely firmware update the mesh routers with a DSL-AX5400 (Optus) router as it's firmware locked, and I want to be able to update the firmware(s) of my mesh network without unplugging them, resetting / removing the mesh, plugging them in my computer, and updating it through the GUI everytime.

Anyways, if someone else had encountered this problem, I've outlined some recovery steps

 

[Tech9]

Got it, you have special requirements. Good you have the recovery skills too.