Install Android 5.0.1 Lollipop on Galaxy S2 I9100 with CM12 Alpha Custom ROM

The latest CyanogenMod Android 5.0.1 Lollipop CM12 custom ROM is available to download for the Galaxy S2 (GT-I9100). Its a good news for those who has Samsung Galaxy S2 I9100 (Exynos 4210), can now install Google’s latest Android Lollipop 5.0.1 on their devices to improve the device’s performance and UI experiences, as you may know, that this ROM is currently available for Nexus and Android Wear devices officially.

CyanogenMod custom ROM is based on the AOSP Android 5.0.1 Lollipop. This is an unofficial and experimental Alpha CM12 version having some issues which are yet to be fixed.

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By using this guide, your device will lose its warranty. However, users can restore the warranty by flashing the stock ROM. The given CyanogenMod CM12 firmware can be only I as a result installed on the Samsung Galaxy S2 (GT-I9100). Do not try to flash this firmware on any other variant of this device, as a result; it might get bricked. Proceed at your risk.

Verify the model of your device, navigate to Settings > About Phone > Mo del Number.

Note: – This ROM is not stable and fully functional.

Bug issues

  • Video Playback
  • Internal Storage (Works partially)
  • Recovery can’t flash files

Before Getting Stared:

  • Remember to take backup of all your sensitive data using Clockwork Mod (CWM) Recovery/ TWRP.
  • Make sure that your device is rooted and has ClockworkMod Recovery tool installed before installing a custom ROM.
  • Download and install the correct USB Drivers for Samsung Galaxy S2 on the PC.
  • The battery level of your Galaxy S2 should be at least about 70%.

Download Required Files:

Steps to Install CyanogenMod Android 5.0.1 Lollipop Alpha CM12 custom ROM on Galaxy S2 (GT-I9100):

Step No 1: – First of all download the Android 5.0 Lollipop Alpha CM12 custom firmware ( and Google Apps from the above-given links on your PC.

Step No 2: – Plug your Galaxy S2 I9100 to PC using its USB data cable.

Step No 3: – Copy file to the root folder of SD card of your phone.

Step No 4: – Now disconnect the device from the PC.

Step No 5: – Power Off the phone to boot into Recovery Mode. Press and hold the Volume Up + Home + Power buttons at the same time.

Step No 6: – While the phone is in the Recovery Mode, select “Wipe data/factory reset” option to erase the phone memory. You can use the Volume keys for navigation and Power button to select options in the Recovery Mode.

Step No 7: – Next, select “wipe cache partition” to clear the cache memory.

Step No 8: – Go back to the CWM Recovery, select “Advanced” and tap “Wipe Dalvik cache.”

9: – Navigate to main recovery menu and tap on “install zip from SD card”.

Step No 10: – Tap on “choose zip from sdcard” and locate the Android 5.0.1 Lollipop ROM .zip file that you have copied to SD card in Step No 3, and start the installation process.

Step No 11: – Navigate to “+++++Go Back+++++” and reboot the Galaxy S2 by selecting “Reboot system now” from the recovery menu once the installation is successfully finished.

Step No 12: – Install Google Apps (Gapps) on your phone by repeating the above steps.

Reboot your Samsung Galaxy S2, it will take about 4 to 5 minutes to complete the booting process for the first time after installation.

You’ve successfully installed the Android 5.0.1 Lollipop on Galaxy S2 I9100 with CyanogenMod Alpha CM12 Custom ROM. Share your experience with us and let us know in the comments area below if you have any issue or question regarding the above flashing process.


Aamir Jamal

An Android Geek and audiophile who love to read and write reviews/tutorials about gadgets and new tech stuff. He has written 1007 guides and other posts.

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