[Xperia Tablet Z Q&A, Help & Troubleshooting] nrbrtx:
Dear XDA-developers!

I have a big problem with my SGP321 with locked bootloader.

What I did to get into it:

1. I had two SGP321 tablets (with different serial numbers, let's call them SN1 and SN2).

2. In TWRP (installed from TabZ-lockeddualrecovery2.8.22-RELEASE.installer.zip) I made backups from SN1 to ext-sdcard.

3. I installed the same TWRP to SN2, then renamed TWRP/SN1 folder on ext-sdcard to TWRP/SN2. (it was very wrong decision!!!! do not repeat my mistake!!!)

4. I restored TWRP/SN2 to SN2 with all default settings (so restored all SN1's partitions /boot, /ta, /system, /cache, /data to SN2 ). (it was very wrong decision!!!! do not repeat my mistake!!!)

For now I have only SN2 in hard-bricked state.

* It blinks red on charge but does not consume current.

* It connects to PC only in flashmode, so fastboot mode is not available.

* Windows 8.1 PC detects it as SOMC Flash Device (USB VID 0x0fce, USB PID 0xadde).

* FlashTool reports the following:

04/004/2016 13:04:17 - INFO - Flashtool Version 0.9.18.6 built on 30-05-2015 22:30:00
04/004/2016 13:04:17 - INFO - Executing search strategies to find proxy selector
04/004/2016 13:04:18 - INFO - No proxy found for IE. Trying next one
04/004/2016 13:04:18 - INFO - No proxy found for firefox. Trying next one
04/004/2016 13:04:18 - INFO - No proxy found for java. Trying next one
04/004/2016 13:04:22 - INFO - Device disconnected
04/004/2016 13:04:36 - INFO - Selected Bundle for Sony Xperia Tablet Z (SGP321). FW release : 10.7.A.0.222. Customization : VMo RU/UA/KZ
04/004/2016 13:04:36 - INFO - Preparing files for flashing
04/005/2016 13:05:02 - INFO - Please connect your device into flashmode.
04/005/2016 13:05:17 - INFO - Device connected in flash mode
04/005/2016 13:05:18 - INFO - Opening device for R/W
04/005/2016 13:05:18 - INFO - Reading device information
04/006/2016 13:06:17 - INFO - Unable to read from phone after having opened it.
04/006/2016 13:06:17 - INFO - trying to continue anyway
04/006/2016 13:06:17 - INFO - Start Flashing
04/006/2016 13:06:17 - INFO - Processing loader.sin
04/006/2016 13:06:17 - INFO - Checking header
[COLOR="Red"]04/006/2016 13:06:17 - ERROR - Processing of loader.sin finished with errors.[/COLOR]
04/006/2016 13:06:17 - INFO - Ending flash session
[COLOR="Red"]04/006/2016 13:06:17 - ERROR - Error in processHeader : 22 : Устройство не опознает команду.[/COLOR]
[COLOR="Red"]04/006/2016 13:06:17 - ERROR - Error flashing. Aborted[/COLOR]
04/006/2016 13:06:17 - INFO - Device disconnected
04/006/2016 13:06:21 - INFO - Device connected in flash mode

* Sony Emma does not detect my tablet.

* Sony PC Companion 2.1 detects my tablet as "Sony / Sony Ericsson phone / tablet" and shows two applications for it - "Support Zone" and "Media Go".

* I have no Trim Area backup for it. But I have this backup for SN1.

* S1tool 30.05.2014 does not detect my tablet.

Sony service says that I need motherboard replacement (but it is out of stock).

Is it possible to repair my tablet at home?

Does SGP321 have test-point for S1tool?

Does it have JTAG and UART connector (as described on Sony Mobile Developer World in "Access UART ports" article)?

What do you recommend to unbrick my tablet?