Spark Core: flashing white and not responding to "mode" button presses (2 of them)

I had 2 Spark Core devices that were setup as temperature monitoring devices on my home wifi. They had been working great up until a few weeks ago when they suddenly went offline (at the same time). I figured I would just need to possibly reprogram them but when I took them down and took a look I found that they were both just blinking white? When I tried to hold down the “mode” button nothing seems to happen (on both devices). I cant seem to reset them without the mode button so I dont know what to do next. I would just think that one of them died except that it was 2 devices at the same time (jan 24 4am) and with the same issue (I had them charting temperature on initialstate.com so I can see exactly when it occured). Anyone seen anything like this? What can I do?

Actually you would use the RESET button to reset the device.

And in order to enter DFU Mode or Firmware Reset, you’d need to press’n’hold MODE an tap RESET.

I think you need to reflash the CC3000 in DFU Mode.