GL-AR300M-16 not responding to factory reset

I bought the above unit 12 months ago and have only used it a few times after setting it up; recently it stopped accepting connection. I have tried the factory reset many times and it is not working. The green light is on and appears to be working but when I try to login to the admin via wifi the IP is not resolving.

Any suggestions on next steps or should I bin this unit and buy something else.

Try to restore completely by uboot debrick.