Update Samsung Galaxy S4 I9505 to Android 5.1 CM12.1 Custom ROM – How to

Shaikh Rafia
Posted 2 years ago

Latest Android 5.1 can now be flashed on Samsung Galaxy S4 model number I9505 using the latest version of the CyanogenMod. CM12.1 Android 5.1 custom firmware brings new features while fixing earlier bugs and problems. Follow these steps to update Galaxy S4 I9505 to Android 5.1 CM12.1.

– Also, read: S6 Edge Craze Pushes Samsung to Produce Massive Quantities of Galaxy S7 Display

Prerequisites to update Galaxy S4 i9505 to Android 5.1 CM12.1:

  • Backup any important data from your Samsung Galaxy S4 I9505 as a complete wipe will be required during the flashing process.
  • Enable USB debugging option on your device: Settings > Development Options > USB debugging.
  • Samsung Galaxy S4 I9505 must be rooted, unlocked and installed with a recovery tool like TWRP or CWM.
  • Your device must be charged to at least 60% of power.

Note: this tutorial is focused on Samsung Galaxy S4 LTE i9505; kindly do not try this guide on other Android & Samsung devices.


How to update Galaxy S4 i9505 to Android 5.1 Lollipop:

Required files: download the CM12.1 Android 5.1 Lollipop custom firmware for Galaxy S4 from here and save it on your computer. Do not extract the contents. Also download Google Apps Package.

  • Connect your Galaxy S4 to your computer using a USB cable and copy the zip file to your phone’s SD card.
  • Disconnect the USB cord and power off your Galaxy S4.
  • Boot it into recovery mode: switch the phone on while pressing and holding Volume Up + Home + Power buttons simultaneously.
  • Perform a Nandroid backup of your current OS: Backup backup and restore on ClockworkMod recovery.
  • Wipe data task: from CWM recovery menu, select wipe data / factory reset and confirm the process.
  • From recovery menu, select install zip from sdcard followed by choose zip from sdcard. Locate the CM12.1 Android 5.1 Lollipop custom firmware and confirm the flashing process.
  • Return back to main recovery menu and reboot your Galaxy S4 I9505 into the new custom ROM. First boot takes a good 5 minutes so please be patient.

Enjoy the latest Lollipop!

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