Flash Official CM 10.2 Nightly ROM for the AT&T Samsung Galaxy S2 I777

Flash CM 10.2 Nightly ROM with Samsung Galaxy S2 AT&T

The CM 10.2 Nightly ROM if now ready to be installed on your AT&T variant of Galaxy S2. Read this entire post and you should be able to complete the installation in ten minutes only.

CyanogenMod 10.2 Nightly ROM is based on AOSP Android 4.3 Jelly Bean and it comes with tons of features for your Galaxy S2 device. You will find both Android 4.3 features, apps as well as CM-based apps created by the ROM’s developers.

Note that since this is a custom ROM and it is quite new, you might find errors and bugs after installing it. That is why you should only use this custom ROM in case you would like to test one of the most popular custom ROMs and the AOSP Android 4.3 OS. Also, you can keep on updating this Nightly builds with newer versions using the CM updater tool in Settings menu.

For this new custom ROM to successfully install on your device at your first attempt, you should take a look at the guidelines below:

  • Use this post only for the Samsung Galaxy S2 AT&T variant. Don’t try to update any other devices using these files as you will end up bricking your device.
  • The SGS2 AT&T smartphone that you’re about to update should be rooted, factory unlocked and running a CWM or TWRP Recovery image.
  • The tutorial will ask you to factory reset the device. This will delete all installed apps data, sms, contacts info, call logs and other similar system data files. This is known as clean installation and you can only skip it in case your device already runs on a previous CM 10.2 Nightly build.
  • If you want to backup installed apps data then you can use Helium app from Google Play Store or Titanium Backup tool.
  • To backup SMS, Call Logs info and APN Internet Settings, then you should use these tools for Android: SMS backup & restore | Call Logs backup & restore | APN Settings Backup & Restore. Root access is needed for some of these applications.
  • Sync your Contacts info with your Gmail account so that you will be able to restore all important phone numbers after your install the new ROM.
  • Enable USB Debugging from Developer Options screen.
  • Make sure that your phone has enough power left in its battery before it discharges completely. In case the device does power off and you didn’t manage to complete the install, then you will need to repeat the entire tutorial once again. Use the comments section to ask for help in case you cannot finish the install.
  • This is a guide for advanced users, do not blame us in case something goes wrong during the installation process.

Continue to the next part of this post when you’re ready to learn how to successfully update your smartphone with the latest CyanogenMod 10.2 Nightlies ROM. Remember not to skip any steps that are listed in this article.

Flash CM 10.2 Nightly ROM Based on Android 4.3 JB for AT&T Galaxy S2:

  1. Download the CM 10.2 Nightly ROM build from here.
    – grab the latest available build.
    – do not unzip the file.
  2. Download Gapps for Android 4.3 ROMs from here.
    – this file has to be flashed after you install the new ROM as it will install all the required Google-based applications you’re phone needs for you to gain full control.
    – do not extract the zip contents.
  3. Connect the phone with your PC. Now move both zip files to your AT&T Galaxy S2 internal storage.
  4. When the files are copied, disconnect the phone from PC. Switch off the smartphone now.
  5. Boot the device into CWM or TWRP Recovery Mode.
    – both custom recovery images are supported by this guide.
  6. When you’re at the main custom Recovery screen you should create a NANDROID Backup file for your currently installed ROM.
    > this will set a restore point for your device and you can use it can something goes wrong with the new ROM.
    – CWM Recovery: select ‘backup and restore’, then confirm the process.
    – TWRP Recovery: press Backup, then select the system files you want to backup and confirm.
  7. Now you need to apply the ‘factory reset’ action before starting the installation:
    – CWM Recovery: select ‘wipe data/ factory reset’. Confirm.
    – TWRP Recovery: press Wipe, then Factory Reset. Confirm.
    > note: if your device is already running on a previous CM 10.2 Nightly build, then you can choose to skip this step.
    > if the phone doesn’t boot with the new ROM and you’ve skipped this step, then you have to restore here and apply factory reset.
  8. Next, install the new CM 10.2 Nightly ROM on your smartphone:
    – CWM Recovery: select ‘install zip from sdcard’, then ‘choose zip from sdcard’. Find the CM 10.2 Nightly zip and confirm the installation.
    – TWRP Recovery: press Install, then browse your phone’s internal SDcard. Load the CM 10.2 Nightly zip and confirm that you wish to install it by sliding to the right the blue button shown at the bottom of the screen.
    > don’t press any buttons while the new ROM is installing.
  9. After CyanogenMod 10.2 Nightly has been flashed with success, you should repeat actions in step 8 for the installation of Gapps file.
  10. When Gapps is flashed, return to the main custom Recovery screen and reboot your smartphone.
  11. The first boot process will take several minutes to complete, enter your Google Account details when the home screen loads.

These were all the steps that you had to follow in order to successfully update your AT&T Samsung Galaxy S2 with CM 10.2 Nightly ROM. Remember that this is a testing build and there is a lot of work before CM team will manage to release a Release Candidate or Stable build.

In case you have problems completing the installation, then you can ask for more help in comments.

If you find way too many bugs and errors, then you should use the ROM NANDROID Backup created in step 6 to restore your device to its previous ROM.

Check the CM Updater tool if you want to continue updating your smartphone with new builds of CM 10.2 Nightlies. Remember that the CyanogenMod team will release new Nightlies on a daily basis and it is always recommended for you to create NANDROID backup every time you want to install such ROMs.