[Q] Help: My Phone dead

I Flash 4.4.2 with ftf and flashtool
after that unlock bootloader without backup :crying:
I cant root so I want to downgrade to 4.2.2 with ftf and flashtool
the ftf was bad downloaded and dead during flash.
when I power on after Sony it says : the software update failed ...
then I try to flash the ftf 4.4.2 again
but this is what happened and ... :crying:


17/042/2014 13:42:40 - INFO - <- This level is successfully initialized
17/042/2014 13:42:40 - INFO - Flashtool Version 0.9.16.0 built on 19-04-2014 19:00:00
17/042/2014 13:42:40 - INFO - Checking if changes have been made to devices folder.
17/042/2014 13:42:40 - INFO - Pulling changes from github
17/042/2014 13:42:40 - ERROR - Cannot sync devices : https://github.com/Androxyde/devices.git: cannot open git-upload-pack
17/042/2014 13:42:45 - INFO - Device disconnected
17/042/2014 13:42:46 - INFO - Selected Bundle for C5502. FW release : 10.5.A.0.230. Customization : TW
17/042/2014 13:42:46 - INFO - Preparing files for flashing
17/043/2014 13:43:15 - INFO - Please connect your device into flashmode.
17/044/2014 13:44:02 - INFO - Device connected in flash mode
17/044/2014 13:44:02 - INFO - Opening device for R/W
17/044/2014 13:44:02 - INFO - Reading device information
17/044/2014 13:44:02 - INFO - Phone ready for flashmode operations.
17/044/2014 13:44:02 - INFO - Current device : C5502 - EP734682ZG - 1272-7047_R2D - 1271-0110_10.5.A.0.230 - GLOBAL-HSPA_10.5.A.0.230
17/044/2014 13:44:02 - INFO - Start Flashing
17/044/2014 13:44:02 - INFO - Processing loader.sin
17/044/2014 13:44:02 - INFO - Checking header
17/044/2014 13:44:02 - INFO - Flashing data
17/044/2014 13:44:02 - INFO - Processing of loader.sin finished.
17/044/2014 13:44:03 - INFO - Loader : S1_Root_5ca3 - Version : APQ8064_39 / Boot version : S1_Boot_Lagan_1.1.1_1 / Bootloader status : ROOTED
17/044/2014 13:44:03 - INFO - Processing partition-image.sin
17/044/2014 13:44:03 - INFO - Checking header
17/044/2014 13:44:03 - INFO - Flashing data
17/044/2014 13:44:03 - INFO - Processing of partition-image.sin finished.
17/044/2014 13:44:03 - INFO - Parsing boot delivery
17/044/2014 13:44:03 - INFO - Phone boot version : S1_Boot_Lagan_1.1.1_1. Boot delivery version : S1_Boot_Lagan_1.1.1_1
17/044/2014 13:44:03 - INFO - Boot delivery up to date. Nothing to do
17/044/2014 13:44:03 - INFO - Processing kernel.sin
17/044/2014 13:44:03 - INFO - Checking header
17/044/2014 13:44:03 - INFO - Flashing data

Then nothing happened

Solved
Just I used Front USB port of the computer. I should use Back USB port