Regaining WiFi connection with Arduino Yun

[oherd]

Recently I received a new Arduino YUN (Invoice # 502370). The Yun worked properly "out of the box". I ran several simple sketches, blinked some LEDs and tested an analog temperature sensor. The Yun easily connected to my netbook (running LUBUNTU 13.10) using wifi via my router, no problem there.
Later I connected the Yun's micro usb power to my netbook's USB port, his time the ArduinoIDE was connected to the Yun via the /dev/ttyACM0 port. Again, simple sketches worked. However, when I unpluged the netbook usb connection and reconnected to a power adapter the wi-fi connection was gone and has not returned.

It appears as though the Yun repeatedly resets. The blue WLAN indicator flashes for about a minute or two then stops, then the TX indicator flashes intermitantly. For a few minutes these LEDs remain off, then the cycle repeats.
So far I've updated the OpenWRT-Yun and tried resetting to factory defaults with no success.
I use YunSerialTerminal sketch to view the monitor. The ifconfig command to the Yun returns ethernet (eth1) and loopback (lo) parameters but the Wlan0 parameters are not reported. I am at a loss as to what else to try. Any advise would be greatly appreciated.

[adafruit_support_rick]

Have you tried pressing the WiFi Reset button, as described on the Yun product page:
http://arduino.cc/en/Main/ArduinoBoardYun

[oherd]

I've used the WLAN reset button several times in both modes, >5sec and >30sec , to attempt to send into a factory reset. The Yun always returns to cycling through what appears to be a repetitive reboot sequence.

[adafruit_support_rick]

Your Yun may be defective. Please email [email protected] with a link to this thread for a replacement Yun