This procedure works even if the physical button on the device has been pressed to shut down Wi-Fi.
Enable telnet
Assuming your device’s IP is 192.168.1.1
:
$ wget --quiet --user=admin --password='password' -O- http://192.168.1.1/setup.cgi?todo=debug; echo
Enter the device
$ telnet 192.168.1.1
Trying 192.168.1.1...
Connected to 192.168.1.1.
Escape character is '^]'.
D7000 login: admin
Password:
#
Set physical button on
# nvram set wifi_btn_on=1
Restart WLAN
# /usr/sbin/rc_app/rc_wlan start