While doing a flash of one of the two Spark Cores I have… all the lights went out… nada. nothing… switched it out with my other Spark Core and it flashed just fine and ran the sketch
At the moment the only indication that someone is home is a short lighting of the D7 LED when the reset button is pushed (the mode switch has no effect) . I cannot “see” it on my Windows 8 USB connection so I can not probe any further. Changed USB cables , changed to a USB power supply…nothing.