[HOWTO][MINI][ST15i] Restore Stock ROM from Cyanogen and other ROMs


I was very disappointed in Cyanogenmod. Although awesome it was with all those features, it was riddled by bugs and stability issues. I slowly realized the hard way that the Xperia Mini is not a very popular phone, so any bugs on it will take time to be fixed. In some cases, maybe not at all. So I’m sticking to rooting my phone with the stock ROM, and will try the official ICS when it comes out. It took me a lot of time to understand how to go about doing these things, around 3 whole days just to get Cyanogen on. And then bombarded with these issues. I had issues after issue, and finally called it quits and returned to stock ROM. I’ll discuss the reasons as to why I jumped off the Cyano-bandwagon in a future post.

Don’t get me wrong, I’m not saying that Cyanogen is a worthless ROM. Infact, the devs did a stupendous job on it, but somehow it still isn’t usable for me for everyday purposes. Atleast, not without slowing me down.

Hopefully this is easy to understand and works well for you. We won’t take any responsibility if this bricks your phone, so do this at your own risk.

GUIDE : To return to stock ROM, use this Flashtool method. I’m assuming you are aware of fastboot as well ( You had to do that while trying to get Cyanogen on). So anyways-

1) Download Flashtool from here
I recommend grabbing the zip instead of the installer and unzip to the root of C: drive. (C:\Flashtool\)

2) Get the Xperia Mini stock ROM ftf file from here

3) Copy the FTF file and go to the Flashtool folder you extracted. Paste it inside the ‘firmwares’ folder.

4) Launch the software and click the ‘Flash’ button (the button with the lightning icon.). Select the ‘Flashmode’ option. If you did like I explained the software will have already found the FTF file, and all you have to do is click OK. Else browse for the file and click OK.

5) Follow the instructions that shows on the software. Note that the service button for our phone is the ‘Volume Down’ key. Use that.

Voila! You will now have returned to Stock firmware. But you still have to do certain things to make the phone completely functional (some things like Wifi, haptic feedback and all dont work when you flash this way).

1) First, root the phone. Use DoomLords method, easiest way.

2) After you’ve done that, switch off the phone. Connect the phone so the fastboot can work (Switch off, connect using the Volume Up key. The blue LED light on top will confirm you’ve connected that way)

3) Remember that FTF file you downloaded? Go to that file, change the extention from ‘ST15i_4.0.1.A.0.283_(1249-8388).ftf’ to ‘ST15i_4.0.1.A.0.283_(1249-8388).rar’ (RAR in the end). Unzip it. Copy the ‘kernel.sin’ file.

4) When you setup fastboot previously (while installing Cyanogen), you would’ve installed Android SDK and some other stuff. Go to the android-sdk folder, navigate to ‘tools’ and paste the ‘kernel.sin’ file inside that folder.
(If you want to learn more about setting up fastboot, look here.)

5) Open command prompt (Cmd.exe). Change the directory to tools inside the android-sdk folder.

For example, in my case it would be
cd C:\android-sdk-windows\tools
Type in

fastboot flash boot kernel.sin

There! Now Wifi, Market and anything else that wasn’t working before should be working now.

Author: Milad Thaha

Graduated as an Architect, but loves animation, story telling and film design. Part geek, part self-proclaimed artist and part psycho.

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