[Xperia Z Q&A, Help & Troubleshooting] AhmedZadjali:
Try it with your own risk, I'm not resposible if you damage your phone and if anything else happens. Below instructions have been tested by me personally and were working.

I can't put any shortcut to my steps, since I'm not going to brick my phone again and test it :p

_______________________________

My phone had an unlock bootloader.

What have I done:

- used my other charger to charge my sony xperia z ( Huawei charger and cable), but yet the screen is off and only red led is appearing

-changed the operating system that I used, since I was running on windows 8, I changed the pc and went to try my luck on windows 8.1

- installed flashtool and drivers( sony xperia z, fastboot and flash mode) with disable driver signature

- Installed Emma from Sony website, I think it helped with the drivers(though I didn't signin to the app)

- connected phone and as it only blinked a red light , on the computer it would automatically detect a new driver and install it

- I noticed now when opening the flashtool that it detected my phone with usb debugging off ( at least it found out something, rather than the first attempt on windows 8 it would show nothing ) , but it disconnects as It shows in the flashtool process

- tried every attempt to get into flash mode or fastboot but I failed

- unplugged the device and made sure it was off (because when I unplug it, the red led is still on, so I hold power button and volume + for few seconds until it turns off and then release those buttons)

- connected again the device, but now even debugging task on flashtool won't appear, ( when connecting it, it shows phone disconnected in the task of flashtool)

- unplugged the device again and now I went back to the flashtool drivers and ticked to install ( sony xperia z, sony xperia z tablet, fastboot and flash mode) and installed the drivers again

- plugged the device and on flashtool I hold power button and volume up(+) , so the red light goes off and I hear from the computer the device connecting and disconnecting , Held those buttons for 10 seconds and then I held volume down (-) only, so the phone led blinked red and green light and quickly went off.

-now my device is connected in flash mode , so I quickly flashed a (ftf) official sony rom

- tasks completed in the flashtool.

- booted the device and the screen is now on and the sony logo appeared( yaaaaay)

- phone booted and shows battery 2% , I ran quickly and charged it and now the phone is back on and everything works great.

... I know this was long to read, but It took my way too long to figure this, I hope that if there is anyone there who has a similar problem to try out what have I done and might get lucky.

Note: my phone had a blank screen and I couldn't do anything that time and I read hundreds of forums about this issue and tried almost everything, but it didn't work with me.

ALL OF THE ABOVE were of my own, I tried things around and messed a little and never thought that I would get my phone back running, but whatever I was trying was really tiring and It took me hours, to finally find myself, unbricking my Sony Xperia Z.

Thank me If this helped you:good:

cheers.:):)