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Flash SentinelROM for the Samsung Galaxy S2 I9100 (Android 4.2.2 Jelly Bean custom ROM)

There is a brand new custom Jelly Bean ROM that is available for the Samsung Galaxy S2 phone. The SentinelROM is based on the popular CM 10.1 build and it should provide an alternative to AOSP ROMs. Use this tutorial and you will learn how to successfully flash all the required files on your smartphone.

It is a custom ROM created by Sentinel196, an XDA member and developer. It uses the CM 10.1 Nightlies as a base and it incorporates LMT Pie Controls, OTA updats are supported for this ROM only, better web browsing, improved 3D gaming experience, improved battery life, support for adding new themes and customize UI. All these enhancements have been added and improved using LINARO toolchain, a bundle of kernels and software tricks that are tweaking the sub-system of your phone.

There are tons of custom ROMs out there but this new one should great for ROM tinkerers, users who like to go from ROM to ROM and test as many as possible before deciding which one should be kept as their daily operating system.

In order to successfully flash the SentinelROM on the Galaxy S2 I9100, you will first have to take a look at the preparation guide below:

  • use this tutorial only with the Samsung Galaxy S2 model number I9100. Don’t try to flash the files you find here on any other Android device.
  • your phone has to be rooted and running a custom Recovery image such as CWM or TWRP. You can’t install any custom ROMs without meeting these requirements.
  • use the custom Recovery Mode and create a full NANDROID backup of your current OS. This will create a restore point for your device and it can be used in case the SentinelROM is unable to boot into normal mode.
  • the tutorial will ask you to ‘wipe data/ factory reset’ the device and this means that the /system partition will be removed from your smartphone. The internal SDcard won’t be affected by the installation.
  • by wiping the data from the system partition, you will lose SMS, Call Logs info and APN Internet Settings. You can use the following tools in order to backup some of those applications’ data: SMS backup & restore | Call Logs backup & restore | APN Settings Backup & Restore. Root access is required for some of these tools.
  • to backup installed apps data, you can use a tool from Google Play Store.
  • sync Contacts with your Gmail account so that you won’t lose any saved phone numbers nor Contacts data.
  • enable USB debugging option from your device’s Developer Options.
  • make sure that the phone’s battery has enough power left before discharging completely.
  • this guide is for advanced users, don’t try to update your smartphone if you don’t know what Recovery Mode does and how it works.
  • we cannot be held responsible in case you lose any data in the process, nor can we be blamed in case you brick the phone.
  • read the entire post and make sure that you don’t skip any steps listed below.

These were all the instructions that you had to go over before getting to the installation process.

If you cannot complete the update, then you should ask for extra help in comments.

How to install SentinelROM 4.60 based on Android 4.2.2 Jelly Bean for the Samsung Galaxy S2 I9100:

  1. Download the SentinelROM zip from HERE or HERE. Save the file on your PC and don’t unzip.
  2. Download Gapps for Android 4.2.2 custom ROMs from HERE. Don’t extract its contents, save the file on your computer.
  3. Connect the smartphone to your PC using the USB data cable.
  4. Copy both zip files to your Galaxy S4 internal SDcard. Disconnect the phone from PC when the files are moved successfully.
  5. Power off your device now completely.
  6. Boot it into CWM Recovery Mode like this: press and hold Volume Up, Home and Power buttons at the same time. Release the buttons when the display flickers and Recovery Mode loads.
    > if you have the TWRP Recovery installed instead of CWM, then you shouldn’t worry, as this guide works with it, too. Just make sure to carefully read the guide and then select the corresponding option to flash the ROM.
  7. Select ‘backup and restore’ option and create a NANDROID backup of the currently installed operating system. This sets a restore point file and that you can use in case the SentinelROM doesn’t want to boot with your phone.
  8. Select ‘wipe data/ factory reset’ option now. Confirm this process and continue to the next step.
  9. Return to the Recovery Mode main menu and select ‘install zip from sdcard’.
  10. Next, select ‘choose zip from SDcard’ and then find the SentinelROM zip. Confirm that you want to install it.
  11. When the new custom ROM file is successfully installed, select once again ‘choose zip from sdcard’. Find the Gapps zip and install.
  12. After you manage to install both files, return to the first menu of CWM Recovery.
  13. Select ‘reboot system now’ and wait for the first boot process of Sentinel Jelly Bean 4.2.2 custom ROM to complete.
  14. Enter your Google Account details and take control over your phone’s functions when the home screen loads.
  15. That’s it, you’ve managed to update your device to Android 4.2.2 using a custom ROM.

NOTE: in case the phone doesn’t go past the Samsung boot animation or it gets into a boot loop, then you will have to remove the phone’s battery. Re-insert the battery after 5 seconds have passed and then you will need to repeat the entire tutorial starting with step 6. This time make sure to apply all the steps that I have listed above and don’t skip the “Factory Reset” action. Custom ROMs are usually acting up whenever you try to flash them using Recovery Mode and, if you try several times, it will eventually install without any further problems.

I hope that you did manage to flash the SentinelROM. Make sure to test all the features and functions that were added with this installation.

If you don’t like how this custom ROM works with your Samsung Galaxy S2 I9100, then you can easily use the NANDROID ROM backup file and restore it using the custom Recovery mode.

Remember that this is a custom Android 4.2.2 Jelly Bean ROM and not an official update release by Samsung. If you find any major bugs you should tell others by posting in comments or heading to the SentinelROM XDA thread here to search for extra help.

Samsung Galaxy S2 Articles