Can't turn it on

Mine is the S3 Classic

I put the watch on the charger, and it shows the lightning bolt. If I push the back button while it's on the charger, it says it's at 100%.

No pressing the back and/or power buttons will turn it on. Either singly or in combination.

On or off the charger, makes no difference.

It won't connect to the phone and all the functions are grayed out in the app, so I believe it to be off.

Is there any way other than trying to press the buttons to get this to turn on?