Install Android 5.1.1 Lollipop on Samsung Galaxy S2

[ I9100 I9100M I9100P I9100T ] Update & Install Android 5.1.1 Lollipop on Samsung Galaxy S2 CM 12.1

How to Install Android 5.1.1 CM 12.1 - 5.0.2 Lollipop on Galaxy S2 I9100

Supported Models Numbers of the Galaxy S2 Devices:

Learn How to Backup & Restore Your Entire Current Android System First Here - Optional For Safety: 

# Downloads 

Odin v3.07

Samsung Mobile Phones USB Driver or

Donate via PayPal:

CM-12-Kernel+Recovery-I9100.tar (Lollipop-Compatible for cm 12 & 12.1) or

ROM ZIP File - New CM 12.1 Android 5.1.1

Gapps For CM 12.1  OR

Alternative Apps Used (Camera,FM Radio,Call Rec.,..etc)
don't install it via CWM or  anything, just extract this zip file normally & will see normal APK apps files, install them as needed


# Frequently Asked Questions 
Control USB Connection
[Method 1]
Go to Settings
Scroll down and tap on Storage
Press the Options key (or tap the ‘Options’ icon in the top right) and select “USB computer connection”
Check “Media device (MTP)”

[Method 2]
Form the "Alternative Apps" Link above, Use an App Called "USB Sharer"
or get it from (Play Store)

Missing Features & Notes
-WiFi Direct & Kies is Not Working in all Custom ROMs.
[ NEW ] Lock-Screen Widgets & Themes are Available in New Builds.

Root is Lost or Not Working ?
1-Download file, copy to internal memory
2-Reboot Into recovery mode and install superSU zip file
3-Reboot system and check the new root status using 'root checker' app for example.

No Network Signal or Cellular Network is not Working ?
-Try another newer or older build number than the one you're now running.
-Go to Settings > about phone  > update > check for updates.
-Toggle Air Plane Mode off and turn it on again, then it reads the sim card and gives you reception, if it doesn't work then update the ROM / change the build you use.
-You may also try Kitkat version with android 4.4.4 which is better than lollipop & more stable & don't has network issues, here:

Odin Doesn't Detect your Phone as in 02:37 ?

Want to go back to Stock ROM with Android 4.1.2 ?

Fix S2 internal Sd By PIT File:
Gapps / Google Apps are Crashing ?
Three possible reasons
[1] You forgot to do a "factory reset" in the recovery before installing the entire ROM.
[2] You installed an incompatible Gapps Package with your android version , if your andorid version is 5.1 then use Gapps for android 5.1 also if your andorid verion is just 5.0 then use Gapps for android 5.0
[3] You tried to install multiple Gapps packages on the system (you have to format the entire '/system'
partition & re-install the ROM again to get the next gapps package work).
-If only one app is crashing then go to the settings,apps,find that app there,tap on it, click "clear data". then try to reopen that app.

# Related Videos
Update Galaxy S2 to Android 4.4.4 Kitkat

How to Change Galaxy S2 Boot-Screen Animation:

Remove The Yellow Triangle & Reset Flash Counter Samsung Galaxy S2

Go back to stock Android 4.1.2 for Galaxy S2

Good Luck


  1. please help me
    i can't reach recovery mode after download from odin3
    please help me....

  2. help me
    Samsung Mobile Phones USB Driver doesn t work

  3. I don't know the name of the files help me

  4. Excellent post!!!. The strategy you have posted on this technology helped me to get into the next level and had lot of information in it.

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  5. Ensure all important data is backed up. Download the CM12 ROM and the GApps (Google Apps) package compatible and Install a custom recovery like TWRP or ClockworkMod on your device. How Game Design Power off your Galaxy S2. Press and hold Volume Up.