Originally Posted by logzz
Are the random black screens a software or hardware issue does anyone know? Otherwise i will have to return my phone if it is hardware related?
No one knows this for sure, at least I don't. This
is what happened with my Z1. So, I took mine to sony & they agreed to give me a new replacement under warranty. I'm not even sure if every Z1 has this issue or not. I know that unchecking optimised backlight triggers a bug on restart, but the black screen issue (with backlight on) had nothing to do with it on mine. Never touched optimised backlight, no rooting / BL unlocking or modding, just the latest stock rom (with a few apps installed from playstore).
Sony Xperia Z1 (C6902)
Stock Rom (Build 14.1.G.2.257)
Locked Bootloader (Unlockable)