Black Screen before Flashtool topic

Hi i just follow the steps
1. Download and install Flashtool on your PC
2. Download the firmware you need (from the list below) and move the .ftf file into the directory C:/Flashtool/firmwares
3. Open Flashtool, click on the lightning symbol ("flash device"), select "Flashmode" and click on "OK"
4. Select the .ftf file of what you downloaded and click on "Flash"
5. Wait for a window to pop up (it may take a few seconds/minutes, just be patient)
6. Now turn off your phone and connect the usb cable to it
7. Push the volume-down button, keep pushing and connect the other end of the usb cable to your PC
8. Once the flashing process has started, you can release the volume button
9. NEVER disconnect the USB cable until it's finished!
http://forum.xda-developers.com/show....php?t=2759934
with 17.1.A.2.36
Mexico - TELCEL - 1281-5458 - LINK1, LINK2
i dont know my Customization number: my screen is black if a use bottons it rumble, i try factory reset with sony mobile but the program say there is no software for this devise
tnx