I need some help ! Bricked XT 925 (Very hard)

[Zhero600]

I´m having a bad time trying to revive a Bricked XT925. I bought it bricked (for repairs only) but the device powers on! I can acces fastboot and recovery (stock). the bootloader is unlocked but every time i try to flash a firmware via RSD or Fastboot, and error returned.
downgraded security version
update gpt_main version failed
preflash validation failed for GPT

I tryed some firmwares (last of Brazil) and some ones of Kitkat version, but none of them helped me.
Alredy tried to flash GPT and TZ only, the same errors. I can´t flash anything. there is something i can do in the stock recovery? The recovery says KDA20. 117-1
The fastboot says :
AP Fastboot Flash Mode (S)
10.9b(*) (sha-07671a2, 2014-10-02, 11:24:45)
eMMC Info: Size 16Gb
Device is UNLOCKED, Status Code : 3
Battery OK
Please enlight me

Thanks in advance

 

[Ustetind]

The thread is about the XT926 for Verizon, but since your issue is identical I guess the same solution works for your phone: http://forum.xda-developers.com/showthread.php?t=2177253
The only difference is that you have to use XT925 firmware.

1. Download the latest stock ROM for your device, then delete these lines in the ROM's xml-file:
<step operation="getvar" var="max-download-size" />
<step operation="oem" var="fb_mode_set" />
<step operation="flash" partition="partition" filename="partition_signed" MD5="0c0917493a29c487f87434a0997c3048" />

2. Follow these steps:
mfastboot.exe flash partition gpt_main0.bin
mfastboot.exe flash logo logo.bin
mfastboot.exe flash system system.img.ext4
mfastboot.exe flash boot boot.img
mfastboot.exe flash fsg fsg.mbn
mfastboot.exe reboot

Get yourself a "Motorola Factory Cable" if your battery is about to dry out.
http://www.ebay.com/itm/5-ft-Fastbo...403?pt=LH_DefaultDomain_0&hash=item3cd9dd0cf3