Boron keeps blinking blue

My boron (2G/3G, ver 1.1.0-rc.1, 3rd party SIM) keeps blinking blue after this color sequence:

Connect power (USB, or batt or both), LED stays first off, then magenta (blinking), yellow (blinking), white (fast), white (solid), blue (listening)

When pushing then the RESET button, the LED stays in solid white, and after a while the color sequence start from beginning.

This persists when removing the power, the battery as well as the USB cable.

Also, I can’t set the Boron in DFU mode.

Any idea how I can get the boron back to normal operation?