Hi all! My HTC one screen has been black on and off for about 4 months now, and I FINALLY found a solution... I tried everything but a hard reset (thank goodness), up until last night, and I'm so happy I stumbled on this. Ok, when your screen is black, you can take a bright flashlight, and at just the right angle pointing at the screen, you can see the icons (I learned this few years back with my incredible that got wet). Go to the display settings and turn up the brightness, and it should come right back to life. I was going to try to save my stuff, but tinkered around first instead, and I'm so glad I did- This worked for me and I hope it helps someone else too! Now if I can only figure out how this happened... Good luck!