No luck with that either.
I sent HTC one to service repair, and the problem came back!
I think we should investigate the issue.
For me, the first time this happened, was the night after I had updated the OS to Android 4.4.2 (Kitkat).
After a hard reset, the screen was coming back sometimes (randomly?), like after keeping it in my pocket for a while, or by itself. After some minutes/hours it would revert to black screen..
I found on the internet there could be a problem with a connector (like in HTC One X), but I didn't want to open and fix it by myself, since the phone is under warranty.
As I said, I sent the phone to HTC service (in Italy). The company in charge for the actual repairing wrote they did "electronic repair", HTC service said the company in charge did just a check and found nothing wrong.
After they "repaired" the phone (and I restored everything as it was using HTC sync manager), the problem has arisen the first time I left the phone uncharged (after 2 weeks, but I suspect it could be the day after). When I charged back and switch on, the screen was gone, once more -.-'
I am about to re-send the phone for repairing, but how can I restore my phone WITHOUT installing Android 4.4.2 then? Just to give it a try, it might be it.
If you have any similar experience please share.
I love this phone, but GOD, 700? for these problems AND this SERVICE??!