Blank screen. Apple Watch series 3
Apple Watch
Apple’s Worldwide Developers Conference to kick off June 10 at 10 a.m. PDT with Keynote address
The Keynote will be available to stream on apple.com, the Apple Developer app, the Apple TV app, and the Apple YouTube channel. On-demand playback will be available after the conclusion of the stream.
The Keynote will be available to stream on apple.com, the Apple Developer app, the Apple TV app, and the Apple YouTube channel. On-demand playback will be available after the conclusion of the stream.
Apple Watch
First ...try a reset by pressing in the crown and side button until you see the Apple logo (about 10 seconds), then release both buttons.
If that doesn't work, read this....fixing-apple-watch-wont-turn-on-dead-device.html
Blank screen. Apple Watch series 3