Kindle touch bricked, im really lost!!

Hi, first of all, im new here, my name is Leandro, im from Argentina.
Sorry for my bad english!! but here is the only place that i found that i think theres people who can help me with my problem
a few months ago, a friend of mine, gave me her kindle. She didnt use it. A Kindle touch, 2012.
I use it with passion for weeks, but then, one day, i cant erase a book in the main page, and i tried to restart the kindle to erase that book.
from this day, the kindle is struck in the tree boy page. no loading bar. from time to time, a battery message appear, but now is fully charged.
i came here and read it with difficult (i speak spanish not much english), the troubles and solutions, but im not developer man, and it cost.
the thing that happen to me is that i cant go to the diags mode. Not with kubrick, not with mfgtool or fastboot.
i enter in mfgtool, with the lib-sub driver i can see the kindle, but every time it reboots with the treeboy. i flash the kernel and the diags, but nothing.
in the mfgtool, once the kindle "restarts" in diags mode (or other mode) it say "MX50 Kindle, please connect device". After that, i can use the fastboot for flash, it does, but nothing happens.
I tried it in windows, not linux. im not a linux user, but i can try if it can be a solution, but i cant find the fastboot for linux.
if theres a driver, a img or anything that im missing, i dont really know what is.
I use the pdf instructions from silver18.
if anyone can help me with another way to try, i really appreciate it
thanks in advance, sorry again for my bad english
Leandro