Good evening everyone. (It's evening here anyway)
I can't imagine this would be a problem in the year 2022 but to anyone who has tried to debrand their pre-Android Sony Ericsson phones you may notice that many guides and tutorials on YouTube no longer work. This is primarily due to their dependence on the Sony Ericsson Update Service and on tools that were behind paywalls that are no longer maintained... I myself spent hours figuring out a solution (though since I'm a noob it probably wouldn't take most people that long...) After browsing through multiple ancient forums, including one in Russian, I finally figured out how this thing generally works.
It seems to boil down to 4 things
1. The filesystem firmware (a file that ends in .fbn)
2. The main system software (a file that ends in .mbn)
3. A set of files that are meant to "finalize" the setup process of your phone (tpa.zip)
4. A program to flash these things onto your phone.
Before you begin you'll need a USB cable to connect your phone to your computer. Your phone will also need to be charged up because the phone doesn't actually display anything while flashing the files. You won't know if the process got cut short except for the error that will pop up in the program on your PC... And the fact that you're phone will be bricked.
Given that everything has to be done offline now only a few tools can still be used. The program you use to flash it is called A2Uploader. Consequently, this guide only works with A2 phones (which W910i is).
The filesystem software, is pretty tricky. Based on my experience, only the firmware from your phone's region would work here. I discovered this forum because this site is the only one hosting these nowadays.
The main system software is pretty straightforward. If you wanna debrand your phone get the ones that have MAIN_GENERIC in the name. This one has a little more flexibility in sources and should still be easy to fine. This forum has it too.
The finalization files are the trickiest. Without them your phone will be stuck with a network configuration error. I don't suppose your carrier still services these phones . I stumbled upon the solution here. I was curious why the poster included the CDA file of a different model in what are allegedly W910i files. Turns out this is the stuff that "finalize" the setup process. You just have to unzip the files navigate till you get to Customize.xml and edit this file. You'll have to edit a few of the parameters. These are:
- The cda-number*
- The cda-revision*
- The model
- Country (presumably)
- Language-variant-name (Find it here)
* For these values you will need a tool called SE CDA File Maker 2.0. This tool gives you the specific values for your phone's model/region. The website is gone now but thank god someone made an archive. The MediaFire link still works but I've also archived it here. The cda-number corresponds to the CDAArticle. Include the dash. the cda-revision is the Revision. Include the "R" and "a" at the start and end. Don't generate a CDA file.
The rest of these are up to your phone's details. I say presumably for country because I'm not sure if this actually contributed to making it work. (I'm a noob remember?) After changing these parameters, rezip the folder and make sure it's named "tpa.zip".
Now open up A2Uploader and click Add to insert the firmware and system software files. (1 and 2 in the list of stuff) Then in MISC files click "..." to add your zip file. After you add these three press FLASH. If you haven't noticed so far there hasn't been anything done to your phone. Turn it off. Then hold the C key while connecting it to your computer with a USB cable. If it sees your phone the process will begin. It will finish when the status bar at the bottom of the console says READY again.
Once the phone has restarted it will take a while to get past the bright blue "Please wait" screen. It might even restart once. This is normal. If everything went well, it will change the theme to the less gaudy default one. Congratulations! You now have a debranded phone!
I would presume that this works with all A2 phones but I haven't anything to test it with so best of luck to non W910 users who're trying to do this too! Let me know. That is if I'm not just shouting into the void of 15 year old tech customization...