[Q] How to unbrick xt1040 (failed downgrade)

[necktru]

Hi everyone

(Sorry mi English, I want to be the more clear possible, I'll be gratefull if answers are equal clear , please)

My actual escenario:
Moto G LTE xt1040 in fastboot 41.16(*), no ROM stock, no custom ROM, the only thing I can do is flash TWRP and it works, but in TWRP I can't flash anything, because I think my partitions are corrupted or gone, If I try to flash CM12 I get an this error :

E:unable to mount '/data'
E:unable to mount '/cache'
E:unable to mount '/system'
...done
E:unable to mount storage

By the other way If I try to flash stock roms like 4.4.3 or 4.4.4 , the command :

mfastboot flash partition gpt.bin

Send me the error:

(bootloader) Preflash validation failed FAILED (remote failure)

Ok, now where I was :

My xt1040 has 4.4.4 stock Latinoamerica, then I unlocked the bootloader, then flash TWRP, then go to CM11, and then to CM12.1 (5.1) ,
I was using CM12.1 for two or three weeks, everything works fine, this week Motorola release the official 5.1 rom for this terminal, and the way to get this official rom was downgrade to 4.4.3, then update to 4.4.4 by OTA, and then flash the 5.1 Rom through stock recovery.

The problem begins when I try to downgrade to 4.4.3, I read the tutorials, download the right ROM, open fastboot and begin to write the commands:

mfastboot flash partition gpt.bin
mfastboot flash motoboot motoboot.img
mfastboot reboot-bootloader
mfastboot flash logo logo.bin
mfastboot flash boot boot.img
mfastboot flash recovery recovery.img
mfastboot flash system system.img_sparsechunk.0
mfastboot flash system system.img_sparsechunk.1
mfastboot flash system system.img_sparsechunk.2
mfastboot flash system system.img_sparsechunk.3
mfastboot flash modem NON-HLOS.bin
mfastboot erase modemst1 
mfastboot erase modemst2 
mfastboot flash fsg fsg.mbn
mfastboot erase cache 
mfastboot erase userdata 
mfastboot reboot

The think is that the first command : mfastboot flash partition gpt.bin sends me the error previously mentioned.
What I did?? I found a gptSTOCK.bin file in other forum, that supossed to be right for the downgrade, I flashed it by fastboot, now the command works fine, I can complete all the commands without error, but the phone restarts and freezes in WARNING BOOTLOADER UNLOCKED screen.

I try to flash TWRP and it works, I can enter recovery but can't flash anything by the UNMOUNT error. Seems like my internal SD is not partitioned correctly or corrupted.

At this point I want to know what makes this gpt.bin file and I don't wanna flash, flash, flash without not know what I'm doing, May be my xt1040 was bricked, I don't know, I think than while fastboot and recovery works, must to be any escape to this situation.

Please If any can help me, I see several people has similar problema with the gpt.bin and unmounted partitions.
I try to do with 4.4.3 rom and 4.4.4 without results.

My problem is to MOUNT the disc partitions (data, system, cache) , I think with that I can flash cm12 or another custom ROM.

Thanks

Martin

 

[iyurcic95]

Hi there!
I have the same problem since February... Mi Moto G XT1040 still bricekd until now.
Yesterday I tried to revive it again, but I couldn't. I'll still trying to taking it back to life again. I'll stay in touch with you and if you can revive your phone, notify me, please!
Regards!
---------------------------------------------------------------------------------------------------------
Hola ahí!
Tengo el mismo problema desde Febrero... Mi Moto G XT1040 sigue brikeado hasta ahora.
Ayer trate de revivirlo de nuevo, pero no pude. Voy a seguir tratando de traerlo a la vida de nuevo. Me mantengo en contacto con vos y si podes revivirlo, por favor avisame!
Saludos!

 

[iyurcic95]

Hey man! I just relive it a few minutes ago! It's perefectly running Android Lollipop 5.1 (AOSP)... The main problem there is when it try to mount "/data", "/system" and "/cache", but I solve it and the phone start like if nothing happened.
I'll make a tutorial, right now I cant, but stay quiet 'couse I already find the solution to the problem!
----------------------------------------------------------------------------
Hey! Acabo de revivirlo hace apenas unos minutos! Esta corriendo perfectamente Android Lollipop 5.1 (AOSP)... El problema principal era cuando trataba de montar "/data", "/system" y "/cache", pero lo solucione y el telefono arranco como si nada hubiera pasado.
Ya voy a hacer un tutorial, ahora mismo no puedo, pero quedate tranquilo que ya le encontre la vuelta al problema!

 

[DjianR]

it works? funcionó?

Hey man! I just relive it a few minutes ago! It's perefectly running Android Lollipop 5.1 (AOSP)... The main problem there is when it try to mount "/data", "/system" and "/cache", but I solve it and the phone start like if nothing happened.
I'll make a tutorial, right now I cant, but stay quiet 'couse I already find the solution to the problem!
----------------------------------------------------------------------------
Hey! Acabo de revivirlo hace apenas unos minutos! Esta corriendo perfectamente Android Lollipop 5.1 (AOSP)... El problema principal era cuando trataba de montar "/data", "/system" y "/cache", pero lo solucione y el telefono arranco como si nada hubiera pasado.
Ya voy a hacer un tutorial, ahora mismo no puedo, pero quedate tranquilo que ya le encontre la vuelta al problema!

Great, how you did? Did you write the tutotial?
------------------------------------------------------------
Genial bro, pero ¿cómo lo hiciste? escribiste el tuto?

 

[DuleKrtola]

Sorry in advance for repeating the question, but this thread is sooooooo loooong ... So here's how I messed up: I had CM12.1 on my xt1039, I downgraded to stock 4.4.4, and then updated to 5.1 (OTA). It worked fine until the battery died and the phone powered off. After that I tried to turn it on, it loaded the fastboot screen for a moment saying sth about partition table and then went blank. I can't get back into fastboot any more. If I plug connect it to my PC and run "lsusb" I can't see anything. Any hope?