Install Android 4.3 JB custom ROM for T-Mobile Samsung Galaxy S2 using Unofficial CM 10.2 Test ROM

Install CM 10.2 Nightly ROM for the Samsung Galaxy

A new unofficial CM 10.2 test build based on Android 4.3 Jelly Bean has been released for the Samsung Galaxy S2 T-Mobile phone. Use this tutorial in order to learn how to successfully flash this custom ROM.

More info about this release can be found in this XDA thread here. In order to make sure that you can flash this new Android 4.3 custom ROM, then you should read the guidelines below:

  • Use this tutorial only with the T-Mobile Samsung Galaxy S2 model number T989.
  • Don’t attempt to update any other devices using the files I’ve listed in this post, as that will brick their firmware.
  • The TMO Galaxy S2 you’re about to update has to be factory unlocked, it should be rooted and running a custom Recovery image like CWM or TWRP.
  • The tutorial will ask you to wipe data and factory reset the device, a task that will delete the contents stored on your device’s system partition: installed apps data files, SMS, Call Logs info and others.
  • To backup data from installed apps use Titanium Backup (here) or the Helyum app from Google Play Store (here).
  • Backup SMS, APN Internet Settings and Call logs info using the following tools for Android: SMS backup & restore | Call Logs backup & restore | APN Settings Backup & Restore. You will need to grand root access for some of these tools.
  • Sync your Contacts data with your Gmail account.
  • Enable USB debugging.
  • Make sure that there is enough power left in your phone’s battery.
  • Note that this guide is for advanced users and you shouldn’t blame us in case you lose data or you brick the phone.
  • Read the entire tutorial and don’t skip any steps that I have listed below.

These were all the guidelines you had to go over before getting to the next part of this guide. If you cannot complete the installation, then you should ask for more help in comments.

How to flash CM 10.2 Android 4.3 JB Unofficial Test ROM for T-Mobile Samsung Galaxy S2 T989:

  1. Download the Unofficial CM 10.2 ROM zip from here or here.
  2. Download the Gapps zip for this ROM from here.
    > both zip files should be saved on your computer or directly to your smartphone’s internal SDcard.
  3. If you didn’t download the files directly on your TMO SGS2, then you will need to connect the phone with your PC via USB cable.
    > move both files to your phone’s internal storage and then disconnect it from your PC.
  4. Power off the T-Mobile Galaxy S2.
  5. Boot the device into CWM / Recovery Mode.
  6. Perform a NANDROID backup of your current ROM:
    > for CWM Recovery devices: select ‘backup and restore’. Confirm.
    > for TWRP Recovery devices: press Backup, then create the backup.
  7. Now you need to apply ‘factory reset’:
    > CWM Recovery: select ‘wipe data/ factory reset’. Confirm.
    > TWRP Recovery: press Wipe, then Factory Reset button. Confirm the process.
  8. Install the new ROM files:
    > CWM Recovery: select ‘install zip from sdcard’, then ‘choose zip from sdcard’ option. Find the CM 10.2 zip and install it.
    > TWRP Recovery: press ‘Install’ then browse the device and load the CM 10.2 zip. Confirm that you want to install it using the blue button shown at the bottom of the screen.
  9. After the ROM is complete, repeat step 8 and install the Gapps zip too. When both files are installed, get back to the main custom Recovery screen.
  10. Reboot your device and wait several minutes for the first boot process to load all the required files.
  11. Enter your Google Account details when the new home screen appears, take control over your device and start testing all its functions and features.

That’s it, you’ve managed to update your Samsung Galaxy S2 T-Mobile device with the latest Unofficial Build of CM 10.2 Test ROM. This is a ROM based on Android 4.3 Jelly Bean and it should bring tons of new features as well as CyanogenMod new apps and functions.

If you didn’t manage to complete the installation at your first attempt, then you should try to repeat the entire tutorial until you manage to flash all files. If you cannot complete the update, then you can ask for more help in comments but make sure to leave a detailed comment at the end of this post so that we will be able to come up with a viable solution for your problems.

In case you don’t like the new ROM, then you can easily restore your T-Mobile Galaxy S2 to its previous ROM using the files created in step 6 and the same custom Recovery Mode.