If your watch's battery is completely discharged, it will not power on. You'll need to charge it before turning it on. If the watch will not power on or if it doesn't seem to charge, the problem could be anything from the battery, connection, the charger, or the watch itself. Give this link a try: https://www.samsung.com/us/support/troubleshooting/TSG01003100/
If you have tried the troubleshooting steps provided, I would recommend a service repair. Another option would be to take the watch back to the place of purchase to see what options they would be able to provide. If you wish to set your device up for service, can you please provide me with the following information in a private message: http://bit.ly/2JH2rq2
Best Contact Number:
Alternate Telephone Number: (If Available)
Bill of Sale:
Hey, just wanted to follow up. Are you still needing further assistance?