Flash Official CM 10.2 Nightly ROM for T-Mobile Samsung Galaxy S2

Flash CM 11 Nightly ROM Galaxy S2 T-Mobile

CyanogenMod 10.2 Nightly ROM has been released for the T-Mobile variant of the Galaxy S2 and now you can use this tutorial in order to successfully update your smartphone with the new OS. Read this entire tutorial and you should be able to flash the new firmware without any problems.

This is one of the most popular custom ROMs currently available for the Galaxy S2 smartphones. Note that after installing this new ROM you will notice that the battery life will decrease. Also, since the Android 4.3 JB hasn’t been released officially for this device, then you also might experience some errors. Make sure to tell us in comments in case you find any major bugs.

The CM 10.2 Nightly is the first stage of CyanogenMod OS build releases based on Android 4.3 AOSP. It packs all the features of the latest Jelly Bean OS along with all the other applications and things added by the CM team. In order to make sure that you install this new custom ROM at your first attempt you should take a look at the guidelines below first:

  • Use this post only with the T-Mobile variant of the Samsung Galaxy S2. This is the SGS2 with the model number T989.
  • Don’t try to flash the files you find in this post on any other Android devices and smartphones.
  • Your smartphone has to be rooted, factory unlocked and running a custom Recovery image such as CWM or TWRP.
  • Both CWM and TWRP Recovery will work with this guide.
  • In the ‘how-to’ part of this tutorial you will find out that a factory reset is needed before flashing the new ROM.
    – if your device already runs on a previous CM 10.2 Nightly build, then you can skip the factory reset. This means that the old version of CyanogenMod 10.2 Nightly can be overwritten with a new build.
    – in case you do skip ‘factory reset’ and then you install the new ROM but the device refuses to boot, then you will need to repeat the tutorial. Factory reset will force the device to boot into normal mode.
  • Factory reset affects the system partition, while the internal storage remains intact. This means that you will lose installed applications data, contacts, SMS and other similar info.
  • If you want to backup SMS, Call logs info and APN Internet Settings, then you can use the following tools for Android: SMS backup & restore | Call Logs backup & restore | APN Settings Backup & Restore. Some of these apps will require root access.
  • If you wish to backup installed applications data, then you can use the Helium app (here) from Google Play Store or the Titanium Backup utility (here).
  • Sync Contacts info with your Gmail account, so that you won’t lose any important phone numbers. After the new ROM is installed you need to enter the same Google account info for all phone numbers to be restored.
  • Enable USB Debugging from Developer Options menu.
  • Use this post only if you’re an advanced Android user. Do not attempt to update your device if you don’t know how to use a custom Recovery.
  • Make sure that the phone’s battery has enough power left before completely discharging. If the phone powers off in the middle of the installation process, then you will be forced to repeat the entire tutorial once again.
  • Note that we cannot be blamed in case you lose data or you brick your smartphone. Read the entire tutorial and don’t skip any steps that I have listed below.

Now that you know all of the above, continue to the next part of this post and learn how to flash the latest build of CyanogenMod 10.2 Nightlies build for your smartphone.

How to flash CM 10.2 Nightly Custom ROM for the T-Mobile Samsung Galaxy S2:

  1. Download the CM 10.2 Nightly ROM from here.
    – get the latest build and don’t unzip the file.
  2. Download Gapps for Android 4.3 custom ROMs from here.
    – this file will install all the Google-based applications.
  3. Connect your smartphone with your computer and then move both zip files to its internal storage. After the files are moved to your Galaxy S2 T-Mobile you can disconnect it from PC.
  4. Power off the smartphone, then boot your device into Custom Recovery Mode.
    – both CWM and TWRP are supported by this tutorial.
  5. First thing that you need to do is to create a full NANDROID backup of your current ROM:
    – CWM Recovery: select ‘backup and restore’, then use the Backup to internal SDcard option to create the file.
    – TWRP Recovery: press Backup, then you need to select the system files you want to save. Confirm.
    > this will create a full restore point that you can use in case the new ROM doesn’t boot successfully after installation.
  6. Next, apply the ‘factory reset’ now before starting the install:
    – CWM Recovery: select ‘wipe data/ factory reset’. Confirm.
    – TWRP Recovery: press Wipe, then Factory Reset button. Confirm the process.
    > NOTE: if your device already runs on a previous CM 10.2 build, then you can skip this step.
  7. Now that you’ve finished all of the above steps, you can start the installation process of CyanogenMod 10.2 Nightly ROM:
    – CWM Recovery: select ‘install zip from sdcard’, then ‘choose zip from sdcard’. Find the CM 10.2 Nightly zip file and confirm the installation.
    – TWRP Recovery: press Install, then browse your internal storage for the CM 10.2 Nightly zip. Confirm that you want to install the new ROM by sliding the blue button at the bottom of the screen.
  8. When the ROM is installed you need to repeat the step 7 actions in order to flash the Gapps zip file.
  9. After both files have been installed with success, then you should return to the main Custom Recovery screen. Reboot your smartphone now.
    – note that the first boot process might take a while before loading all the new files. Don’t press any buttons until the home screen appears.
  10. Enter your Google Account info in order to take control over your smartphone. That’s it, you’ve updated your phone and now you can start testing the ROM.

In case the new ROM doesn’t finish the first boot process after ten minutes or the phone enters into a boot loop, then you will need to power it off completely. After that you need to repeat the entire tutorial once again in order to manage to install the CM 10.2 Nightly ROM successfully. In case you’re having any other problems use the comments section to ask for our help.

If you like this new ROM and you wish to upgrade it with new CyanogenMod 10.2 Nightly builds, then you can use the CM Updater tool under Settings menu. Simply use the tool and search for Nightlies new releases, then hit the Download and Install button for the ROM to be flashed on your phone.

If you don’t like this CM 10.2 Nightly ROM then you can easily restore your phone to its previously installed ROM using the backup files created in step 4. If you have any other questions about this custom ROM or Galaxy S2 T-Mobile then you can leave them below.