[Sony Xperia Miro, Tipo (Dual), J, E] attila_feher:
Clarifications

Czesc,

Guys, After almost a day of try-and-fail it worked.

However, let's translate to human language some of the steps:

A: First be aware that you'll loose everything that you have on your phone, except for the SD card.

If you have your contacts, apps, games (and e.g. you want to remember the last level in your games) back-up your phone first. Because my phone initially wasn't rooted, I used ClockWorkMod's Carbon. It can get some special privileges via ADB and then it can backup more than the regular backup apps can do. Still, I lost my desktop arrangement, wake-up alarms, ringtone settings etc, but I could keep all my important stuff.

B. Prerequisites. You need:

- A rooted Xperia J. If your xperia is not yet rooted, the easiest way is to go back to ROM version 11.0.A.3.28 that can be rooted by Bin4ry's method. Search google or XDA-developers for Root_with_Restore_by_Bin4ry_v18.zip or newer.

- "Debug mode" and "mock locations" must be always on in the settings of your phone: see Setting->Developer options in case that you're a noob.

- Flashtool - it's a software that can push "flashable" files/ROM images to your Sony Xperia phone. The version of the Flashtool that I have, by default, does not support Xperia J, so you need to use the ST26.ftd file (import in Flashtool or simply copy its content -- it is a renamed Zip -- to the device definitions directory).

With Flashtool you can easily get back to version 11.0.A.3.28, then you can root it. For example, you can connect your Xperia J, drag-and-drop ST26i_11.0.A.3.28_WE.ftf to Flashtool, and it will tell you what to do next. Read the next comments, though.

- On Xperia J, you get into "flash mode" by the following way: you switch off the phone, press and hold the "volume-down" button, then, with Flashtool running on your PC, connect your USB cable to the phone. Flashtool could mistakenly show you to press and hold the "back" button.

Be careful that with Flashtool, pushing a full ROM image could take something like 40-50 minutes. In my case the screen of my PC got stuck and it went black meanwhile. So don't rush to disconnect, because you would get an incomplete image on the phone and end up in a bootloop. If this happens, just flash again the same image, but be patient this time.

C. How to do:

Basically follow termobulbulator's steps from the first page. What actually happens:

- First you have root your phone if you haven't done it already (using an older version of the ROM and Bin4ry's method; as mentioned, I recommend ROM version 11.0.A.3.28 )

- Install ClockWorkMod Recovery (CWM). Because your bootloader is locked, there is no straightforward way to do it. For this reason, these guys use a clever trick, they replace your phone's switched-off battery charging gauge with a bootable CWM, and you can then apply a system image that you download to your SD card. Your phone "thinks" that it just displays on-screen an animated charging battery, but instead you run a ROM recovery tool.

- Be careful not to use a cheap Class-2 SD card because it won't work.

- After this, it is important to switch off the phone by removing its battery, and NOT to switch it on until you are not ready to get again into Flash mode, see the next step.

- The final step is to "enable" the image that you loaded with the FTF mentioned in the last step. This must be done again with Flashtool.

Thanks termobulbulator!

Enjoy your JB :)