I notice that when I'm in sync mode it blinks blue until complete. I recently had some sort of brown out and I had an amber light blinking along with the blue. I just unplugged it for a week since I had a CM11a backup with heyu on it. When I plugged the wm100 back in and synced the time and timers it started working again. Not sure what that did? but it's working now so I'm not going to fix it.