Black screen on Venu 3

The last Friday the screen of my Venu 3 has gone black (9.18v). What can I do to make it work again?

I tried to turn off and turn on several times, but the screen remains black. I tried to "crash" the watch (pressing repeatedly power and back buttons), the watch I think crash, because makes a long vibration, but the screen remains black.

I don't know what else to try to get the screen to work.

I have talked with the Garmin Support but they told me that I need to talk with the "beta developers" because I am in the beta program.....

But until now...my watch do not works :-(

serial number: 7ZJ048414

Beta version: 9.18