I pressed and held the power button for 10 seconds, fixed the problem right away with a simple reboot.
I've had my watch 5 days, after getting it hooked up (which took 5 hours, long story) I freaked out when I couldn't get the screen to work. I know it was on and charged, but black.
Mine lasted less than a month, unfortunatelly this solution did not help. Any other ideas please???
I bought the watch while in the US, I'm not any more. Here the technical assistance hasn't even tried to turn it on :(
Screen just went black but still connected to phone and recieved notifications and sounds whilst black, held power button in for a few seconds while on charge and boom rebooted, worked for me thanks!