Apple Watch

You have to press in both buttons until you see the Apple logo, then release. (it takes approximately 10 seconds). If you still have a problem call a nearby Apple store and make an appointment with their Genius Bar.

The white Apple logo is the first screen which appears during power up and starting the watch. It should change after some seconds to a circle/ring which slowly fills as the software loads. Leave your watch on the charger for an hour or so and see if you can get enough power into the battery to let it start completely. If the white apple keeps reappearing persistently while it is charging it means the battery is so discharged it doesn't have enough reserve to start the watch before the voltage drops and it makes another restart. That’s a bad sign if that happens, and you will need to Contact Support and arrange to get your watch checked by Apple Service, particularly the battery.