Info 2 [GUIDE] Flash Stock ROM with Flashtool (also Downgrading)

This is the tutorial for reflashing Stock SONY ROM. We have some custom ROM but if you want to go back to Stock you can follow this thread/tutorial!

Created: 23-02-2014
Updated: 11-03-2014
Latest Android build released by Sony: 12.1.A.1.201


Let's begin shall we..

First you need to download the correct ftf file for your device/operator or needs. This can be done here: http://forum.xda-developers.com/show....php?t=2311964 Also you need to download either the 4.1.2 or 4.3 update from there. If you can not find it you can ask it in there!

Second thing; You will need a program called Flashtool for this. You can download this here: http://forum.xda-developers.com/showthread.php?t=920746
For Windows 8 and 8.1 users I also recommend you to read this thread: http://forum.xda-developers.com/show....php?t=2095087
(Above link is a how to for installing the proper drivers for Windows 8/8.1 clients)

After the installation of Flashtool and the proper drivers you need to move the downloaded ftf file into the correct folder. Location can be found here: C:/Flashtool/Firmware

Before you can flash back you need to check for the following things:
  • Bootloader locked? If not you wont have BE2/OTA/PCC etc (for unlocking and relocking: http://forum.xda-developers.com/show....php?t=2354721 )
  • I've made backups of my important files that are stored on my phone?
  • Battery at atleast 50%?
  • I have patience?
  • I got something to do meanwhile?

Let's get started:

1: Open Flashtool:


Flashtool(.exe) for 32Bits systems and Flashtool64(.exe) for 64Bits systems

2: Press the Lightningbolt picture and select Flashmode

This will give another screen.

3: Select the downloaded ftf. (In this case 2.254)

Make sure that all the wipes are checked and the others are unchecked. This is to prevent any bootloops or other problems after downgrading.

4: Press Flash and the next two lines will be added to the flashtool log

The files are being prepared and checked. Have a bit of patience please.

5: Turn off your phone and turn it back on into Flashmode

After this the process will start.


After flashing you can remove your phone and boot it up. You will have 4.1.2 back on your device

FAQ


- My Phone wont stay into flashmode
> Turn it off, wait a few minutes and turn it back into flashmode

- Flashtool wont recognise my phone
> Make sure you have the proper drivers installed. See C://Flashtool/Drivers

- Flashing failed
> Problem depends on the error code given by Flashtool. Post the problem here and perhaps we can help

- Got a bootloop
> Reflash again

- Even after reflash I got into a bootloop
> Turn off your phone via the small button behind the batterycover and wait a few minutes. Then try again. If that doesnt work you need to flash again.

- Booting takes ages
> This is normal. The entire cache needs to be rebuild. Patience my dear..

- After flashing and booting my phone is laggy.
> Reboot device and wait a bit. The phone needs to fully reset and boot itself. Have some patience dear.

- Do I need to unlock my bootloader to use flashtool
> NO!

- Can I unlock my bootloader with flashtool?
> NO!

- Can I relock my bootloader with flashtool?
> Yes