Xperia Z Ultra freezes on "blank' (black) screen after error 100 while updating to Android 5.0

[tarjan1]

I tried to upgrade my C6843 (Sony Xperia Z Ultra brazilian version) through Sony PC Companion, follow all of the steps by software but during the process had error 100 (Failed Update Engine). 

My Internet connection was working 100% and there was no restriction on Sony PC Companion access information from the Internet (access was released in firewall). The process was stopped and since then my cell phone no longer works. When switched on a screen appears with the word SONY (in the middle of the screen) and Xperia (at the bottom) and right after the screen goes dark (but with backlight, indicating that the power is on) and does not respond to any other commands, shutting down only by hard reset (by pressing the POWER button and VOLUME + at the same time).

Unlike the tutorials I found on the internet, the phone shows no screen stating that the update process was unsuccessful (only the screen that read SONY XPERIA and then the screen goes "off" and after this locks the cell). When I connect the USB cable the cell phone is not recognized by the PC, it is not possible to rerun the process of updating the Sony PC Companion.

Already sought information about how to restore the unit to the internet, but all the tutorials I've read indicate how to recover from the device connection to the PC via the USB cable, which is not working with me since the device is not being detected by Windows 7.

Appears the "old" firmware was erased and nothing was inserted on the place. Can anyone help to try to recover my cell phone?

[Thommo]

Try performing a system repair using PC Companion as this will often fix issues - This will factory reset your phone and erase all data

Switch off your phone and unplug from Pc (Hold volume up and power for around 10 seconds)
Start PC Companion and select Support zone then Update my phone/tablet then in Blue Repair my phone/tablet and follow the on screen instructions - When prompted connect your phone still switched off holding volume down or back button - This should start the repair or reformat process

If you are using Windows 8/8.1 or a 64bit operating system then adjust the settings for PC Companion and run in compatibility mode and chose Windows 7 or XP

[tarjan1]

Thank you Moderator, I finally succeeded restart my phone update process again but every time I try to update it presents the same error message: ".. Unable to unload the device software Check your Internet connection again later" followed options: RETRY or CLOSE.

If I press the RETRY it immediately presents the same message, if I press the CLOSE it presents ERROR 100 (failure on update engine).

I've deactivated the firewall and the antivirus, set up the PC Companion to run in compatibility mode with Windows XP SP3 (my OS is Windows 7/64) and to run as administrator.

I have also entered the Task Manager and manually eliminated almost all applications that were running in the background (left only the processes of OS), but nothing changed: keep getting the same error message 100.

[Thommo]

Try running PCC in compatibility mode as it could be an issue with the 64bit engine and Flashmode

[tarjan1]

I finally managed to restore my Android Xperia Z Ultra.
I tried everything on my computer: set up for use in Windows XP compatibility mode, using as an administrator, deactivated antivirus and firewall and still without work. I tried to boot the computer in Safe Mode with network access (by pressing F8 during the boot) and kept getting the error message 100.

Finally I tried to install on the computer of my wife (Windows 8/64) and the process was entirely without fault without making any adjustment.

The error 100 was possibly occurring for some mismatch in my computer hardware.

Many thanks to the moderator for the support and commitment.