Have been trying to find some information about this, but can't seem to get Google to show me a similar problem to what I have. I got an Apple Watch 4 about 6 weeks ago. Everyone has worked well so far until today. I got in the car this morning and couldn't get the screen on. I started again and saw the apple logo and everyone seemed to be back to normal, but a few minutes later I went to check my clock and it got stuck on black again. I taped the screen lightly to see if it was just the wrist effect that didn't work, but while pressing the screen, I accidentally started calling someone through the clock. I tried another reset and again the apple logo showed but then the screen came up empty. I can still navigate through the menus by taking screenshots on the clock and watching them on my iphone so I know the clock is still working in the background, just not showing anything. I have tried a power reset and know it has worked as it prevents me from taking a screenshot while it is booting, but it does not bring back the screen. I have also entered the power saving mode and then back to normal mode, but the screen is still black.